- Aang from Avatar: The Last Airbender certainly qualifies, particularly in the earlier episodes. He does undergo some serious Character Development, though, once he discovers the gravity of the circumstances he and his friends are in. His Keet-ness is taken Up to Eleven when an Earth Kingdom general, who is attemtping to invoke the Avatar State for military use, has him drink the Avaverse's equivalent of Red Bull.
- GIR from Invader Zim. His electronic robot voice coupled with his bizarre enthusiasm for everything makes him a very notable example.
- Clancy and Ping from Julius Jr.. Both of them are generally excited over the littlest things.
- Looney Tunes: The Bob Clampett version of Daffy Duck is famous for being a hyperactive Large Ham. Even after his character became more bitter and snarky, he still retains quite a bit of his energetic nature, particularly when he's happy.
- Braeburn of My Little Pony: Friendship Is Magic has shades of this and Motor Mouth. He's enthusiastic, usually quite cheerful, and can only be stopped talking by his cousin Applejack.
- Pym from Next Avengers: Heroes of Tomorrow.
"Maybe he was the Knight! Or the Pixie!""Maybe he was the Knight!"
- From Phineas and Ferb, the eponymous Phineas is an enthusiastic, energized and overall very friendly, extroverted kid - by contrast, his step brother Ferb is very subdued and quiet. However, he's no less friendly or curious.
- Shifty Dingo from Blinky Bill. Especially when he's in a good mood. "I'm going to a party! I'm going to a party!" (bangs drum repeatedly)
- Sanjay from Sanjay and Craig has a high-pitched, bombastic voice and is shown to be a very cheerful Nice Guy.
- The Fairly OddParents!: Timmy Turner is this arguably. He has No Indoor Voice and is very very energetic. He, in fact, is the center of a Toy Ship, several in fact.
- The Evil Midnight Bomber What Bombs at Midnight from The Tick, who is constantly rattling off conversations about his evilness to no one in particular and has severe trouble not bursting out phrases like "Down with government!" during normal conversation.
- Buster Baxter from Arthur is easily the most fun loving out of Arthur's friends. Whenever he's feeling down, it's usually for a pretty good reason.
- Cliff, one of the two judges from the talent tv show "Wow!" from World of Winx is a definite keet, since, unlike his Grumpy Bear fellow judge Margot, he is excited by what the contestants bring to the show.
- Wander from Wander over Yonder who is always happy, fun loving and upbeat.
- Jack Spicer of Xiaolin Showdown becomes this temporarily upon being turned good by one of the artifacts. He spins and twirls, all the while talking about how being good puts the entire world at your fingertips. Needless to say, This freaks out the heroes and they want desperately to turn him back into the Big Bad they know.