ok theres the dragonheart mage which is for those with any draconic heritage to get full caster progression a breath weapon and free feats. thats probably what your thinking off

so what did they do for the 5e dragonborn did they just remove the dragonborn inability to bread or completely change the fluff

I've had quite a few, since my players have often been completely unpredictable. For example, in The Village of Homlett one of the NPCs is a 0-level  human tailor who for some strange reason, wields the heavy crossbow and dagger as a 7th level fighter -with an additional +2 to hit and damage. One of the PCs decided he had to have padded armor of a certain color (red, IIRC) and while bargaining for the tailor's services, convinced him to join the expedition to the Moathouse and later, the Temple of Elemental Evil. In spite of having only two hit points, the tailor survived without a scratch. Once the party completed the two adventures, I made the tailor a 7th level fighter -a fitting "battlefield promotion"- and he hung around for the duration of the campaign.

Another was an ogre in the Moathouse who was charmed by the party's magic-user and became his bodyguard for several adventures.

The third was Turuko the monk, who joined and tried to betray the party in the Moathouse. For reasons I can't remember, the party spared his life and he changed his tune and became a valued henchman/party member for a long time.

So that's three in one module and all three took me by surprise when I was the DM.

My group has Excited Guy.  That's his name now, his real one being lost to the ages.

Excited Guy was first encountered in a Mage game.  The PCs needed some info and we were directed to this guy who could help.  What we found was an NPC who, for the first time in the campaign, was genuinely happy and excited to help us.  He didn't want anything in return, or try hide anything, or all those things you expect to run into when you need to get help.  He just wanted to help.

The group took such a liking to him that we often included him in on things past the original situation.  He continued to be excited and loved hanging around with the PCs and being whatever help he could.

Since then Excited Guy has shown up in a few different campaigns spanning a few different games (Mage, CthulhuTech, DeadLands, Pathfinder, Anima).  Every time he is ready to help the PCs out and do the best job he can because he is just so darn excited and happy to help us out.

I had a simple minor villain NPC for Villains & Vigilantes named "Puzzler". He was a "joke villain" who was meant only for a one-off appearance. However, that one appearance was so much over-the-top fun, he became my go-to nuisance bad guy. My PCs both loved him and loathed him. Loved him because he was fun to go toe-to-toe with. Loathed him because their public reputation always took a hit as Puzzler managed to always come out on top and humiliate the PCs. Eventually, to save his own hide, Puzzler had to team up with the PCs for a campaign-altering scenario. And when he reformed and needed to be trained as a hero, who do you think he turned to? Yup, for a Riddler/Ambush Bug hybrid one-off joke bad guy, "Puzz" became (and still is) one of my longest-running NPCs.

That would be the Klaxon family.

Steve Klaxon and his ancestors and descendants have followed us across five game systems.

Steve was one of the guys on our Rogue Trader cruiser whose job it was to wear a flashing red hat and scream 'WAH WAH WAH' when the ship ran into trouble. (Hey it is 40k, everything is done manually,including calls to battlestations... I also wanted to rip-off Kentucky Fried Movie...)

This became irksome to the captain who had him jettisoned, and ever since then any minor yet unexpectedly irksome NPC in a new game usually ends up as a Klaxon. (His most recent appearance was as a revenant in our brief 5e game that had come back to hunt down the PC that had brutally killed it earlier... It turned out he was reasonable for a vengeance maddened undead abomination and joined the party for a bit with the promise that he could kill the PC on the last day of his year back.)

In my DCC game, I had a guy who owned a "curiosity shop", that claimed to have "just about everything".  The whole place was a cluttered mess, and if the PCs ever asked "Do you have x", he'd ALWAYS answer "we do not! But we have this.." and lead them to some completely unrelated object that may or may not be of any use or interest to them (I'd pick the object, usually, by rolling completely randomly for it).  
He was meant to be a one-time joke, but the players were so amused by it that they constantly came back, every session, for as long as they were based in that city.