I'm just going to post a number of monster conversions I've done in this thread. They are for Swords & Wizardry White Box and BFRPG, and are easily compatible with older D&D games. Hopefully, you guys will find some use for these. They have all been posted in my blog over the last few years.

S&W:WB

Winged Horrors
Armor Class: 5 [16]
HD: 3
Attacks: Bite (1d6)
Special: Deepvision, Fear
Move: 40 (flying)
HDE/XP: 4/240

Winged horrors are aberrations that can appear when summoned by a mage. They appear as a pitch-black orb with bat-wings. They have an open maw filled with rows of teeth. They have no discernable eyes or other features. They fly constantly, and appear to never tire. Their skin is leathery and tough, and if they are cut they bleed a green ichor. They emit a high-pitched shriek as they are attacking, but are otherwise silent.

Deepvision: Winged horrors can see in pitch blackness, including magical darkness.

Fear: Anyone who sees a winged horror must make a Saving Throw or run in panic away from the creature for 1d6 rounds.

S&W:WB

Neckbiters
Armor Class: 6 [13]
Hit Dice: 2
Attacks: bite (1d6)
Special: Leap
Saves: 17
Move: 20
HDE/XP: 2/30
Neckbiters are vicious little monsters. They are semi-intelligent, and often set up ambushes. They stand two feet tall, and weigh about 30 pounds. They have very sharp teeth, and wicked little claws. They are cyclopean, but still manage to judge distances well. They can leap up to 10 feet, and then attack. They move very quickly. They are carnivores, and prefer to feed on the intelligent races, as they enjoy inflicting pain on their prey. They are known to "play" with their food before killing it, if they have a large advantage. If not, they try to kill as quickly as possible, leaping for the throat, which is how they gained their name.

S&W: WB

Yuan Ti, Abomination
Armor Class: 0 [19]
Hit Dice: 9
Attacks: sword (1d6)
Special: Spells
Move: 9
HDE/XP: 10/1400

Yuan Ti abominations have a snake body and snake head, with the scaled human torso and arms. They can use weapons, and cast spells. They can see in the dark, including magical darkness. They can cast the following spells once per day: Cause Fear, Dark I, Sticks to Snakes, Neutralize Poison, Suggestion, and Polymorph.

Cause Fear: Target must make a Saving Throw or run away from the caster for 1d6 rounds.
Suggestion: Target must make a Saving Throw or follow a one sentence command from the caster. Target will not attack his friends or himself.

Ruins & Ronin (based on S&W: WB)

Constructs, Wicker
Armor Class: 7 [12]
Hit Dice: 13
Attacks: No-dachi (3d6)
Special: See Below
Move: 8
HDE/XP: 13/2300

Wicker Constructs are made of wicker. They often appear as fully armored samurai, and utilize a wicker no-dachi as their weapon. Due to their great strength, they do extra damage with their sword. They are healed by Growth spells (and do not increase in size). They are only harmed by +1 or better weapons, or fire-based spells. Normal fire damage slows them. No other spells affect them.

S&W: WB

Skaven
Armor Class: 6 [13]
HD: see below
Attacks: by weapon (+ special)
Movement: 12
HDE/XP Value:
Clanrat: 1/15 XP
Globadier: 4/120 XP
Assassin: 5/240 XP
Plaguebearer: 2/35 XP
Plague Monk: 5/240 XP
Packmaster: 3/65 XP
Jezzail: 3/65 XP
Rat Ogre: 4/120 XP
Grey Seer: 10/1,400 XP
Stormvermin: 4/120 XP
Warpfire Throwers: 3/65 XP

Skaven are humanoid rats, nearly man-size in height. They walk on their hind legs and they use their hands as would a human. They are typically brown or black, though whites are seen. Their eyes are a deep red and reflect light, making them appear to glow at night. They are worshipers of a god called the Horned Rat. It appears that their goal is the complete domination of the land and the slavery of all other races. This includes orcs and goblins as well as humans and demihumans. As such, they have no allies among the other races.

All skaven have infravision to 60 feet. They speak Skaven, though some (20%) speak Common. Skaven also have the ability to speak with rats of any type, and often use rats as spies and forward lookouts. Skaven are constantly exposed to disease, and thus gain a +4 on their saves when exposed to some form of plague. Skaven are never attacked by rats of any type, though only packmasters can control rats.

Clanrats: The majority of skaven encountered are clanrats (~85%). They are usually encountered in packs of 3 to 30. They conform to the listed statistics, and have no special abilities. If clanrats are preparing for a major battle, they don chainmail and have an AC of 5 [14]. They wield spears and short swords in battle.

Globadiers are skaven who know how to make poison wind globes. These globes are small crystal balls, which are hurled at the enemy. When the globes strike, they shatter, releasing a poison gas that covers a 10 foot area. Anyone who breathes the gas must make a saving throw or take 20 points of damage. Those who make their saves take 5 points of damage. One globe can be hurled per round, with a range of 10/20/30. If a blunt object strikes a globadier, he must make a saving throw or 1 to 3 globes will explode. Note that this will almost definitely kill anyone near him. Other skaven tend to give globadiers a wide berth during combat for this very reason. Globadiers wear gas masks, which grant them immunity to the poison gas. The mask only protects vs. globadier poison, other gaseous attacks are unaffected by it. Globadiers also carry a short sword for engaging in melee.

Assassins are similar to regular skaven except that they have 2 Hit Dice and have several special abilities. They are very stealthy, and can only be noticed on a successful Find Secret Doors roll if they have hidden. If they successfully attack someone who has not located them, they inflict double damage with their weapon. Assassins also gain a +1 on their initiative roll. They use contact poison on their blade (save or take 1d6 damage).

Plaguebearers go into battle wielding censers filled with a liquid that causes disease to beings which come into contact with it. Plaguebearers do not retreat, fighting to the death, as they are among the most insane skaven of the clans. Someone hit by a censer must make a saving throw or catch a disease, which has the following effects: victim loses one point of constitution and strength per day. If either ability reaches 0 the victim dies. The spell Cure Disease is the only known cure for the ailment. Once the spell is cast on a victim, he regains one point of strength and constitution per day, up to his normal score. The censer acts as a flail in combat.

Plague monks are dangerous opponents. For one thing, they have 2 Hit Dice. They also may cast the following spells once per day: Curse, Cause Light Wounds, Cause Fear, Cause Moderate Wounds, and Cause Disease. Plague monks fight with a short sword in each hand. (House Rule: Roll 2d6, take the highest number.) The Cause Fear spell forces the target to make a Saving Throw or run away from the Plague Monk as fast as he can for 1d6 rounds.

Packmasters are skaven who have an innate ability to command rats, equivalent to a Charm Animal spell. They will be leading 4 - 16 giant rats when encountered. If in an area populated by rats, they can summon an additional giant rat each round along with engaging in normal combat. Packmasters are the only beings able to cause rats to attack skaven; even human mages or clerics can't do this. Packmasters have 2 HD, with maximum hit points. They fight with a short sword in one hand and a whip in the other. (House Rule: Roll 2d6, take the highest number.) Packmasters also command Rat Ogres, once they are experienced or have enough prestige within their clan.

Jezzail are skaven who have mastered the art of the rifle. They are the only creatures that know the secret of creating smokepowder. They will never reveal the secret of its creation. Jezzail are totally dedicated to their weapons, and will wield only their rifle in combat. They disdain all other weapons. A unit of jezzail firing in unison can decimate the best knights, as some humans have learned too late. Jezzail will go to any length to recover lost weapons. If a human is seen with a gun, he will be attacked at the earliest opportunity (like when he goes to sleep).
Jezzail Rifle: Dmg 1d6, ROF 1 per 2 rounds, Range 70 ft, Weight 8 lb, Cost -, Armor only provides half protection (ex. plate mail only provides -3/+3 armor bonus).

Grey Seers are extremely rare. There are only about 20 of them in any given world. They have 5 HD, but cast spells as a 10th level mage. They have a bodyguard of 30 stormvermin with them at all times. They are the masters of the skaven race, and all skaven defer to them. Seers maintain a library and a laboratory much as human mages do. Each Grey Seer has his own selection of spells, but they all tend to prefer spells that cause lots of damage (such as fireballs), as well as using curses and spells that cause disease or prolonged pain.

Rat Ogres are huge, mutated rat men. They spend much of their lives in a berserk rage, as they live in a constant state of pain. They are also not very intelligent. A packmaster will accompany any Rat Ogres encountered, keeping them under control and preventing them from slaying the skaven nearby. Rat Ogres are statistically identical to normal Ogres.

Stormvermin are the skaven warrior elite. They average 6 feet in height and are quite muscular (+1 to hit and damage with a weapon). They have 3 HD, with maximum hit points. They wear plate mail (AC 3 [16]) and wield two-handed swords, great axes, and halberds in combat. They are immune to fear (including spells, dragons, etc). They are often used as bodyguards by the clan elite, as well as being excellent shock troops in battle. Stormvermin typically aren't too bright, and as such are rarely encountered in any type of leadership capacity (not counting leading other Stormvermin).

Warpfire throwers work in groups of two, carrying their famed weapon. A warpfire thrower spits out a ball of green fire 50 yards, which explodes and injures everything within a 10-foot radius. Those caught within the blast radius take 3d6 points of damage or 1d6 damage if they make a saving throw. Warpfire throwers are the only beings who know the secret of their weapon. Note that a thrower cannot be fired during any round in which its bearers have moved, and can only be fired once every 3 rounds in any case. If one of the bearers is killed, the remaining skaven can still fire the weapon, but will be unable to move it anywhere. Warpfire throwers will let no other skaven touch their weapon and will destroy it if it cannot be removed from danger. Humans who manage to capture an intact warpfire thrower will be unable to get it to work. In fact, in all such cases where this is attempted, the weapon explodes, causing 20d6 damage to all within 40 feet. While the warpfire thrower is a powerful weapon, any medium level mage can easily best it with fireballs or lightning bolts. As such, warpfire thrower teams either avoid mages totally during combat, or attempt to sneak up on them and kill them with one shot. A warpfire thrower looks like a World War II flamethrower, with one skaven carrying the fuel canisters on its back and the other holding the tubing and nozzle. These skaven also arm themselves with short swords in case they are forced into melee.
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Skaven are extremely territorial, and often war with each other. A different clan rules each area, and if members of another clan enter the area, it is considered an act of war. These wars are often very vicious, and are one of the main reasons the skaven do not overrun everyone just by numbers.

Skaven also fight amongst themselves to determine rank within the clan. These fights are seldom fatal, but all skaven are scarred, with many missing an eye or ear. The Grey Seers encourage this behavior, as the Horned Rat says that only the strong may rule. Grey Seers are above inter-clan warfare, and often visit each other. No skaven would dare assault a Seer or his bodyguards. Seers also work together, though not well. The skaven are also slavers. They enslave those they defeat in battle, forcing them to do all the menial labor. Eventually, they will eat the slave, if they are short on food.

S&W:WB

Murlocs
Armor Class: 6 [13]
Hit Dice: 1-1
Attacks: Weapon
Special: Breathe water
Move: 9/swim 9
HDE/XP: < 1/10

Murlocs are small fish-men that inhabit coastal areas, often setting up small villages in isolated coves. They can swim very quickly, and can breathe underwater. They fight with spears. They are very aggressive, despite their small stature, and often swarm at enemies.

Murloc  Shamans
Armor Class: 6 [13]
Hit Dice: 1
Attacks: Weapon/Spells
Special: Breathe water, Spells
Move: 9/swim 9
HDE/XP: 1/15

Murloc shamans lead the murloc tribes. They can cast magic missile three times per day.

S&W: WB

The Joker

Armor Class:     0 [19]
Hit Dice:            10
Attacks:             1d6 (fist)/1d6 + "shakes" poison (hand crossbow, see below for poison)
Special:              Gadgets (see below), Followers
Move:                9
HDE/XP:           12/2,000

The Joker is a terrible figure in a city's underworld. He commits criminal capers, and usually leaves a few bodies behind at each one. He loves leaving clues for intelligent adventurers to try and find him. He is extremely intelligent, though completely psychotic, and will not fall into obvious traps. In combat, he will target magic-users first, then clerics, then fighters. The Joker is immune to Hold spells, and will often send his lackeys to delay adventurers while he escapes if it looks like the battle is going poorly.

The Joker has a few gadgets that he can use any given round. When activating a gadget, it acts as if he cast a spell.


Gadgets:
Fear Gas Lapel Flower: Target must make a Saving Throw or run away from the caster for 1d6 rounds.
Hypnotic Pocket Watch: Target must make a Saving Throw or follow a one sentence command from the caster. Target will not attack his friends or himself.
Sleep Gas Egg: Characters within five feet must make a successful Saving Throw or immediately fall asleep for 1d6 rounds.
Hand Buzzer: The Joker attacks character who is effectively AC 9 [10] for this attack. If struck, the character takes 3d6 electric damage. Can only be used once per encounter (the gadget needs recharged after a successful hit).
Magic Top Hat: The Joker can pull one random monster from the hat during an encounter. The monster will fight fanatically against anyone the Joker desires. The monster vanishes after one turn. (Choose the monster based on PC abilities).

Lackeys: The Joker will have 1d6 Fighters of levels 1 to 3 with him. These fighters are armed with maces and leather armor and have AC 7 [12]. They are also fanatical, and will fight till the bitter end. If encountered at his Hideout, there will be 3d6 Fighters present.

Gear:
Hand Crossbow: Dmg 1d6, Range 15/30/45, ROF 1/2.

"Shakes" Poison: Target must Save or take 1d3 damage for 5 rounds. While affected by the poison, the character shakes severely and cannot cast spells and suffers a -2 to hit penalty with missile weapons.

BFRPG

Banshee
Armor Class: 19
Hit Dice: 7**
No. of Attacks: 1 fist/1 wail
Damage: 1d8/1d10
Movement: 30'
No. Appearing: 1
Save As: Magic-User 7
Morale: 9
Treasure Type: special; M, N, special in lair
XP: 800

Banshees are the spirits of young women who were murdered, usually by a lover. They haunt the area around where they died. They appear as translucent women, much as they did in life. All banshees carry a silver comb worth 100 gp. When first encountered, they are often found combing their hair.
Banshees may be turned as Vampires. They may only be struck by magical weapons or spells. In combat, they will always target men before women.
They are intelligent and may be bargained with. If anyone in the party is a male of the race of their murderer, they will attack that individual. They generally won't attack women unless they are attacked first.
Banshees are very strong and do 1d8 damage when striking someone. Once per turn they can wail, which causes 1d10 damage in a 30'cone. When the banshee is first encountered, characters must Save vs. Paralysis or run away in fear for 1d6 rounds.

BFRPG

Beastmen
Armor Class: 13 (14 with shield)
Hit Dice: 2*
No. of Attacks: 2 (weapon/bite)
Damage: by weapon / 1d6 (special)
Movement: 30’
No. Appearing: 1d6 (4d6 in lair)
Save As: Fighter 2
Morale: 9
Treasure Type:  Q, S (B in lair)
XP: 100

Beastmen are strange mixes of humanoid and animal, with many having the head or legs of an animal race. Most beastmen have the head, legs, and hooves of goats. Other varieties have been seen, such as hybrids of bears, large cats, and wolves.

All beastmen are filthy creatures and havens for disease. Anyone bitten by a beastman must save vs. disease with a -2 penalty or begin to lose one point of Constitution per day. If their Constitution drops to zero, they die. The disease can only be cured with magical healing.

All beastmen appear to be male. They reproduce by capturing females of other races and raping them. They then keep the women prisoners until they give birth. Baby beastmen eat their way out of their mother’s stomach, so the birth is always fatal for the mother. Beastmen appear to be able to reproduce with all sentient races. The baby is always a beastman male, and often looks nothing like either of its parents.

Beastmen raiders typically attack a village at night, killing all of the men and children, and herding the women back to their camps. The slaughtered men and children are typically eaten, with many beastmen carrying a hacked-off arm or leg home as a snack.

Beastmen are quite tough, and have a natural Armor Class of 13. They use weapons and shields, preferring spears, swords, and axes. Each beastman also has either fangs or tusks, which they use in combat. They have darkvision to 60 feet, allowing them to easily raid at night.

Beastmen live in forests, preferably close to farmlands that they can easily raid. Within the forest, they live in caves or villages that they’ve taken from other races. They do not build things themselves.

Beastmen have no allies among the monster races. Even orcs and goblins hate them, as the beastmen view all other races as food sources and potential breeders.

BFRPG

Steel Spider
Armor Class: 18
Hit Dice: 5**
No. of Attacks: 2 forelegs
Damage: 1d6 each
Movement: 40'
No. Appearing: 1
Save As: Fighter 5
Morale: 12
Treasure Type: special
XP: 450
Steel spiders are constructs used by mages to guard their possessions. They are made of steel, with jeweled eyes (worth 100 gp if removed). Their main body is only one foot in diameter, with each leg being two feet long. They are often painted black or brown, to help blend in with their surroundings.
Being constructs, they are immune to fear, charm, and similar spells. They take an additional 1d6 damage per hit from any attack that rusts metal. They only take half damage from non-magical weapons.
They have darkvision to 120'. They can climb walls, even hanging upside down. They are resistant to magic, and gain a +4 bonus to Saves vs. Wands or Spells.
Steel spiders are often placed in ambush, and can only be detected on a 1 on 1d6 if they are hidden. They can leap 30 feet, and automatically gain surprise when making a leap attack if they have not already been detected.

BFRPG

(I had posted this in a different thread, but figured I should fit it in with all the others.)

Draugr
Armor Class: 17
Hit Dice: 9**
No. of Attacks: 1 (weapon)
Damage: 1d10+3
Movement: 30'
No. Appearing: 1
Save As: Fighter 9
Morale: 12
Treasure Type: B, M
XP: 1,225

Draugr are the undead remains of ancient nord kings. They appear as a skeleton wearing ancient plate mail. They wield an ancient nord two-handed sword in combat. They are only encountered in ancient crypts.

Draugr can see invisible opponents.

Once per turn, they can use a dragon shout. Anyone in front of the draugr when he shouts must make a Save vs. Spells or drop anything they are holding in their hands. Items dropped will scatter 10 feet behind the character.

Draugr may be turned as vampires. Draugr are immune to Sleep, Charm, and Hold spells.

Nice work!  Thanks for the monsters!  I am definitely going to use the Skaven (with the serial numbers filed off), as I like to have minions of the evil Rat God around to make mischief...and Skaven make good servitors of the Rat God to be lurking behind the human cultists.

Also intrigued by the Joker.  Don't know how I'd use him personally, but I think the idea of porting over other genre characters to fantasy has some potential.  Especially villains.  You just have to be careful to avoid farce - unless that is what you are going for.


-TGA

A friend of mine once used the joker in a similar fashion to Q from star trek having him drop by unannounced every time he had a lul in the campaign that needed a fast and not too serious one shot of some kind, the joker as godlike mischief maker worked really well in that game especially as it gave the group and gm a break from the usual serious business of adventuring.

Joker, Skaven AND Bahshee for basic D&D?

I love you Dan. Srsly .