The player characters in Cartoon Cartoon Summer Resort, as opposed to being established Cartoon Network characters, all originated from pilots featured in Cartoon Network's 2000 "The Big Pick" event, where viewers could vote on their favorite cartoon from a selection of pilots, with the most popular being made into a full series - Uncle Gus originated from "Uncle Gus", Longhair originated from "Longhair and Doubledome", Vivian originated from "Foe Paws", and Prickles the Cactus originated from "Prickles the Cactus".

Neither of the two pilots from the 2000 Big Pick that would be picked up as full Cartoon Cartoons (Whatever Happened to Robot Jones? and The Grim Adventures of Billy & Mandy) were featured in Summer Resort.