- The Nostalgia Critic: In "Battle of the Commercials", while reviewing the commercial for the Spider-Man Atari 2600 game, among other things, the Critic misinterprets the Green Goblin's "You're running out of fluid!" line as "You're running out of Bloo wigs!", and shows a picture of Bloo wearing a wig.
- SuperMarioLogan: In "Jeffy's Foster Home!", when Mario asks Officer Brooklyn T. Guy what would happen if he beat Jeffy in front of him, and Brooklyn tells him that he'd have to take Jeffy to a foster home. Brooklyn then brings up Foster's Home For Imaginary Friends, saying it was a good show, and also asking what the name of the blue imaginary friend was, before realizing his name was Bloo.
- MAD: Bloo appears among the Cartoon Network characters in "Once Upon a Toon".
- The Powerpuff Girls: Mac, Bloo and Frankie make cameos in "The Powerpuff Girls Rule!!!"
- Robot Chicken: A sketch from "Joel Hurwitz" has a little girl visit Foster's. After rejecting Bloo, Wilt, Eduardo, and Coco, she chooses to adopt Tyler Durden from Fight Club as her new imaginary friend.
- Wander over Yonder:
- Stok, a character that appears in "The Time Bomb", looks similar to Bendy. Don't worry, unlike Bendy he gets his comeuppance.
- Bloo makes a cameo during the finale.