Kender are the halflings of the Dragonlance setting. They look like similar to halflings, but tend to always look like slightly exotic little children with pointed ears and well tanned skin, and often act with childlike wonder and innocence. They often wear their hair in a topknot. IIRC they used to be "normal" halflings in the distant past, but a powerful artifact called the Greystone mutated halflings into Kender.
They are famous for being kleptomanicacs. Culturally, they have no real concept of individual property, so if they see something they like they tend to take it (even if they don't realize they are doing it, and normally don't realize that anyone else would take offense). They are also known for their ability to taunt and tease mercilessly, goading their opponents into foolish acts. They are also utterly fearless.
Traditional Kender weapons include the hoopak, a spear with a copper spearhead and a slingshot on the other end, and made a vaguely musical sound when spun overhead. Most traditional kender weapons could be used as improvised musical instruments.
I don't remember the game-mechanic differences or how they are depicted in the current Dragonlance book, but you didn't have it you could play them with just a 3.5 Halfling. Maybe change their racial skill bonuses to Sleight of Hand, Open Lock and Disable Device and Bluff instead of Climb, Jump, Move Silently and Listen.