Foster's Home for Imaginary Friends/Trivia

Hey, It's That Guy!: A guy looking suspiciously like Arthur Dent is on the side of the road in the episode where Bloo hijacks a bus.
- Mac walks into a bowling alley and passes by The Dude, Donny, and Walter.
Hey, It's That Voice!: Where do we start?
- Bloo is the second version of Friend Owl
  - He's also the ruler of Castle Oblivion. How fitting...
    - In Japan, his voice actor is Noriaki Sugiyama (Sasuke)
- Eduardo is SpongeBob SquarePants and Spyro in the latter two of the original Insomniac trilogy.
  - Who is also now Rabbit, as of the 2011 movie.
- Coco, Madame Foster, and Cheese are The Flea, Nora Wakeman, and Snap, respectively.
- Frankie and Goo are Vicky and Wubbzy.
- Wilt is Hermes Conrad, Green Lantern and Samurai Jack.
- Mr. Herriman is Professor Utonium and Yoda.
- Believe it or not, Terrence is Tara Strong.
- Mac is Pence.
What Could Have Been: In the earliest sketches of the show, Mac was blonde and had shorter hair.