Chowder and The Special Letter

Cast

 * Chowder as Thomas
 * Jimmy (Ed, Edd, n Eddy) as Percy
 * Filbert (Rocko's Modern Life) as Toby
 * Jock (Lady & The Tramp) as Donald
 * Twilight Sparkle and Pinkie Pie (My Little Pony: Friendship is Magic) as Annie and Clarabel
 * Kermit the Frog (Muppets) as Sir Topham Hatt
 * Taran (The Black Cauldron) as Edward (does not speak)
 * Wreck-It Ralph as Henry (does not speak)
 * Cookie Monster (Sesame Street) as Gordon (does not speak)
 * Alex (Madagascar) as James (does not speak)
 * Rocko (Rocko's Modern Life) as Duck (does not speak)
 * Trusty (Lady & The Tramp) as Douglas (does not speak)
 * Gumball (The Amazing World of Gumball) as Oliver (does not speak)
 * Yakko and Wakko (Animaniacs) as Bill and Ben (do not speak)
 * Mufasa (The Lion King) as BoCo (does not speak)
 * Inez (Cyberchase) as Mavis (does not speak)
 * Olivia (The Great Mouse Detective) as Henrietta (cameo)
 * Pops (Regular Show) as Jeremiah Jobling (cameo)
 * Beret Girl (An Extremely Goofy Movie) as The Refreshment Lady (cameo)
 * Sonic the Hedgehog as Bertie (mentioned)