Franchise: Cartoon Network

MK Ultra Girls was a scrapped children's cartoon based on the Mortal Kombat franchise being produced at Warner Bros. Animation around 2020, which would have revolved around aged-down versions of Mortal Kombat characters going to school. The character designs were done by YouTuber Pan-Pizza and the series got very far into production, but was scrapped after a change in leadership at Warner Bros. Animation. Alongside an action figure line, an iOS game based on the engine of Mortal Kombat X Mobile was planned. According to the Redditor who originally leaked the show's existence, NetherRealm "did okay getting these designs in 3D but it's far from done. Progress has halted on the game which is also effecting [sic] the show."

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.