Foster's Home for Imaginary Friends - Season 6 - Eps 8: Destination: Imagination (3)
Frankie is tired of working without being thanked. One day, a toy box is discovered at Foster's front door. Frankie is ordered to take it to the attic and leave it alone, but she knows there is an imaginary friend trapped inside, and opens the box to find it. When she looks inside, she falls into a strange imaginary world. There, she gets treated like a princess by a mysterious imaginary friend. After tackling certain bizarre toy box trials and tribulations, Bloo, Mac, Wilt, Eduardo, and Coco discover Frankie's whereabouts and set out to rescue her from this strange world. This is the first and only episode to have a TV-PG rating.
About Foster's Home for Imaginary Friends

Title: Foster's Home for Imaginary Friends
First Air Date: 2004-08-13
Last Air Date: 2009-05-03
Status: Ended
Rating: 7.786/10 (from 476 votes)
Language: EN
Seasons: 7
Total Episodes: 79
Network: Cartoon Network
Genres: Kids, Animation, Family, Sci-Fi & Fantasy, Comedy
Production Companies: Cartoon Network Studios
Synopsis
Children who create imaginary friends usually take care of them until they are 7-8 years old. Imaginary friends, left on their own after this event, continue to live in this home founded by old Madam Foster.
Cast

Sean Marquette
Mac (voice)

Keith Ferguson
Bloo (voice)

Tom Kenny
Eduardo (voice)

Phil LaMarr
Wilt (voice)

Grey DeLisle
Frankie (voice)

Tom Kane
Mr. Herriman (voice)

Candi Milo
Coco / Madame Foster (voice)