Kender
Kender are a fantasy race in Dungeons & Dragons' Dragonlance setting. They are basically Halflings with double-doses of ADHD and kleptomania thrown in. No one apparently saw how terrible a decision that was. They survive getting the shit kicked out of them only because every one of the little shits seems to be wearing plot armor which they undoubtedly stole from more interesting species now tragically extinct.
Most of their fluff involves them stealing things and getting pissed when they are accused of it ("It must have fallen into my pocket"). What fluff doesn't involve theft directly is more focused on how much everyone loves the cute little Kender anyway. They aren't even decent comedy relief since they have childlike naïvety and "d'awwww" written into the race description.
The only person who likes playing Kender is That Guy. Some are so brazen as to try to play a Kender outside of the Dragonlance setting. In this situation, feel free to have your PC use lethal force against the offending character, the rest of the party will gladly help you. Don't even allow the little shit to suicide his character; justice must be done and he cannot be allowed to die on his own terms.
They generally cause a lot of rage in anyone who reads anything about them.
Ironically, 2e produced only two other groups that were quite as Chaotic Stupid as Kender, and neither of them are as hated. Planescape gave us the Xaositects faction (who do approach Kender-levels of annoying in the eyes of many DMs -- a Kender Xaositect PC is generally regarded as a concept horrifying enough to make a DM's brain explode) and the Slaad (who were explicitly done up as monsters to avoid and/or kill, so far less irritating by any measure).
Even the other two races of Dragonlance generally hated by DMs and players alike aren't as bad as Kender. The Tinker Gnomes are generally idiots, but can actually be kind of funny. Sometimes. Plus even the writers at TSR got a little jab at them by noting how normal gnomes like to hunt down and destroy Tinker Gnome spelljammers in Spelljammer. As for Gully Dwarves, frankly, most people prefer to pretend they never existed, since an entire race of ugly, smelly, hairy, retarded baby-people is the kind of concept that should have been purged with fire at birth.
So, basically they're like young children stuck in the "sticky fingers" stage of development. Except they don't feel guilty about it later.
The good news is that WOTC realized that maybe no one likes Kender and thus has excluded them from the 5e Player's Handbook- time will tell if they disallow them from being a playable race altogether. Kender would make great monsters- like Kobolds but smarter, use their cuteness to lull travellers into a false sense of security while constantly swiping their stuff.
Horrifically, Kender and humans can actually breed together, creating abominations called half-kender, who inherit the kender knack for sticky fingers but aren't so cutesy that they don't realise that stealing is wrong. How this is possible is a long story, but basically, kender descend from tinker gnomes (making them cousins of dwarfs, who have the same ancestry), who descend from humans cursed by Reorx. This is why Krynn is also home to half-gnomes and half-dwarves.
There's no good reason why Kender should have survived this long anyways:
- Physically diminutive in an environment rife with monsters, with nothing but agility and pickpocketing to defend themselves with.
- There's no trade nor commerce with outsiders; nobody would let a kender get near a marketplace or bazaar, and even if they were trading one-on-one at village borders, some other Kender would probably steal the wares while you were still discussing the prices.
- Hell, being pathological liars about theft means any non-Kenders would treat them as little sociopaths.
- There's no construction; the minute you turn your back on any materials, it's gone to be used in someone else's building project. (and while they were stealing your building materials someone else was stealing theirs.)
- No Kender is going to have the attention span to do the boring but necessary work like stockpiling food, learning to write, or digging latrines.
- The only way they could survive a frosty winter is by raiding villages and travellers with their cute smiles and compulsive thieving behaviour... leaving any villages that didn't exterminate the long-haired rats starving themselves.