What happens when children outgrow their imaginary friends? They take them to Madame Foster's Home for Imaginary Friends, a vast Victorian mansion with endless rooms and hundreds of thought-up playmates. At the heart of the story is Blooregard (aka Bloo), an imaginary friend created by an eight-year-old boy named Mac. Although he's usually shy, Mac feels confident when Bloo's around. Bloo, on the other hand, is bold and self-assured, and often gets himself into a mess by acting before he thinks. Follow the adventures of Mac and Bloo in a world where imaginary friends actually come to life. Nothing is ever mundane when you hang out at "Foster's Home for Imaginary Friends"!
Blooregard is convinced that Cheese looks like an alien after watching a sci-fi movie about brain-eating spacemen and reading a tabloid newspaper with a picture that has an alien that looks like him, so he sends a message to outer space in essence inviting them to Earth.
When the Fosters gang goes to a swap meet, Edwardo gets his hands on a $100 bill after a thief loses it. Everyone gets greedy and they want the bill causing chaos.
Bloo goes with Madame Foster in a hurry, thinking that they'll join the rest of the crew at the annual county fair, but that shortcut finds both Blooregard and Madame Foster at a fabric store.
After visiting a retirement home, Blooregard wants to leave Madame Foster's and move there. To do that he takes a bath long enough to be all pruned.
Bloo tells Mac an outlandish story.
Bloo and the gang try out as a rock and roll band.
Blooregard believes that Mac, even at his age, is getting married.
Bloo befriends a rich kid named Barry Bling, heir to a paddleball fortune, but things don't seem what they ought to be for Mac.
Tickets won in a radio contest cause a rift between Mac, Bloo, and Frankie
Blooregard plans to play the ultimate trick on Halloween after tying down Mac onto a bed preventing another sugar rush, but when things go awry, most of the main characters of the residence turn into zombies.
When Eduardo tells little white lies to those at the nursery, including a little child named Scrappy that admires Eduardo, he has to cover them up before they catch up to him.
A retelling of "The Big Cheese" from the view of a little pea, who against all odds, helps Frankie turn a negative into a positive.