In the Foster's universe, imaginary friends take physical form and become real as soon as children think them up. Once the children outgrow them, the friends move to Foster's Home for Imaginary Friends, where they stay until other children come to adopt them. The home is run by the elderly Madame Foster, its founder; her imaginary friend Mr. Herriman, the business manager; and her granddaughter Frankie, who handles day-to-day operations.
Mac is an eight-year-old boy, whom his mother told that he needs to give up his friend Bloo, who hears about Foster's and thinks it will be a perfect place for him to stay. Bloo moves in with the lanky and one-armed Wilt, the scary-looking but cowardly Eduardo, and the bizarre bird/airplane/tree friend Coco. He is saddened to learn that staying at Foster's makes him eligible for adoption by another child, but eventually Madame Foster makes a special deal: as long as Mac visits every day, Bloo can live there and not be adopted.
In the Foster's Home for Imaginary Friends universe, imaginary friends (or "friends" for short) become physical beings the instant a child imagines them; unlike how the concept often works on other shows, an imaginary friend takes physical and emotional form after a child creates specific details about that character. Unfortunately for them, the children eventually outgrow them around ages 7–8. When this happens, the friends are left to fend for themselves. Foster's Home for Imaginary Friends was founded by the elderly Madame Foster to provide a foster home for abandoned imaginary friends.
There are (according to "Setting a President") 1,340 imaginary friends in Foster's Home; however, at the end of "Emancipation Complication", Madame Foster states that there are 2,038 imaginary friends currently residing in the house, plus Bloo and Mr. Herriman. The house motto is "Where good ideas are not forgotten".
The inspiration came when McCracken and his wife, Lauren Faust, adopted a pair of dogs from an adoption shelter. McCracken wondered how things would be if there was a similar place for childhood imaginary friends.
- Mac – A bright, creative, sensitive and somewhat shy 8-year-old boy and Bloo's creator and best friend who visits Foster's. Mac is often the voice of reason among his friends (especially Bloo) when they're making decisions. However, his good nature tends to make him somewhat naive. He is very attached to Bloo and it is shown in episodes such as "House of Bloos" and "Duchess of Wails" that his biggest fear is never seeing him again because Bloo is what keeps him happy and cheerful and vice versa. Mac becomes extremely high and hyperactive to the point of a rabid mania when he eats sugar. Once in this state, he will become impossible to control and will often become obsessed with seeking any other source of sugar. He also has a crush on Frankie. Mac and Bloo are the two main protagonists of the series. He is voiced by Sean Marquette.
- Bloo – Mac's 5-year-old imaginary friend and best friend who resembles a simple, domed cylinder. Bloo is sometimes self-centered, egotistic, and narcissistic, and has a knack for getting in trouble. However, he still has a good heart and apologizes for his actions. Bloo loves paddleballs even though he can't make the ball hit the paddle (though the only time he was able to do it was in the episode "Let Your Hare Down"). His full name is "Blooregard Q. Kazoo". He became increasingly mischievous over the run over the series and can be a show-off. He is voiced by Keith Ferguson.
- Wilt – A very friendly, very tall, red-colored friend with a stubby left arm and crooked left eyestalk (which he describes as "wonky"). However, in "Good Wilt Hunting", it is discovered that he was not always this way; he was injured in a fateful accident during a basketball game, leaving his arm crushed and his eye injured. Wilt exhibits consummate good sportsmanship, which he applies to every part of life he can. He is considered the nicest person at Foster's and is known for being excessively polite and apologetic, saying "I'm sorry" in almost every sentence. Wilt has a big heart, is frequently cool and collected, and, only on very rare occasions shows anger at all. His name is an homage to NBA star Wilt Chamberlain. Wilt was shown to be created by Jordan Michaels, a basketball star (and a homage to Michael Jordan). His oversized basketball shoes always squeak against the floor/ground, no matter what surface he is walking on. He is voiced by Phil LaMarr.
- Eduardo – A Spanish guardian friend. Despite his large size, overwhelming strength, and menacing demeanor, Eduardo is docile, timid, lacks confidence, and is very compassionate. He has a toddler-like nature, crying at minor negative occurrences, and being scared of almost everything. However, he can be ferocious if angered or in the circumstance that danger befalls his friends. Eduardo has a fondness for potatoes, dogs, and his cuddly toys. His creator, Nina Valerosa, is now a police officer. He is voiced by Tom Kenny.
- Coco – A bird-airplane-palm tree friend who can only say (or write) her name at various speeds and different emphases. A talent unique to her is her ability to lay colorful, plastic eggs containing a plethora of objects from customized baseball cards to money, at will. Mac, Bloo, Eduardo, Frankie, Wilt, and others usually understand her when she speaks, and often translate for her (though Wilt once admits that he has no idea what she attempts to convey). Despite her helter-skelter appearance and quirky behavior, she can demonstrate a perceived intelligence, principle and kindness. No one knows who her creator is as she was found on an island by two scientists named Adam and Douglass, in reference to the late writer, Douglas Adams. She is voiced by Candi Milo.
- Frankie – Madame Foster's 22-year-old granddaughter, addressed as "Miss Frances" by Mr. Herriman. Frankie is the caregiver at Foster's and helps keep everything in order. In spite of Mr. Herriman's fussiness and fixation with rules and cleanliness, having to take care of everyone and everything in the house, and Bloo's mischief-making (all of which cause her tremendous stress), she is usually very friendly and easy-going. According to her driver's license, she was born on July 25, 1984. She is voiced by Grey DeLisle.
- Mr. Herriman – A gray and white anthropomorphic lop ear rabbit friend imagined by Madame Foster who speaks with a British accent. He wears a tailcoat, white gloves and a top hat, as well as a monocle over his left eye (though it is sometimes seen over his right eye). He is in charge of the house (the "President" of Foster's), is extremely strict about the house rules (or just politeness and order in general), and is often found punishing Bloo for his various misdemeanors. It was revealed in "Busted" that the reason Mr. Herriman is so hard on Bloo is because he feels that, given that he is allowed to stay at Foster's even though he still has an owner, he has already broken one of the main house rules. He is extremely fond of his creator Madame Foster, harboring great respect and loyalty to her, even at her most prominent levels of unabashed pep and energy. Mr. Herriman may be considered unruly Madame Foster's superego. On the other hand, Herriman has a love/hate relationship with Frankie, usually working with her to preserve order at Foster's, yet just as often scolding her for what he perceives (often inaccurately) as "laziness" and "immaturity" from her part (usually stemming from the fact that the amount of work she has to do is too much for her to get all of it done in certain time frames). However, at the end of the 90-minute special "Destination: Imagination", Herriman admits that he was wrong and finally comes to respect and appreciate Frankie. Also he has a fear of dogs and is easily scared out of his wits whenever he comes across a dog as shown in the episodes "Who Let the Dogs In?", and "Setting a President". He is voiced by Tom Kane.
- Madame Foster – The founder of Foster's and the grandmother of Frankie. She is said to have been named after the famous snowboarding champion Ryan Foster. Madame Foster is elderly but has child-like boundless energy, and enjoys life to the fullest. Her imaginary friend is Mr. Herriman, whom she imagined when she was a child and never gave up. Like Bloo, Madame Foster occasionally becomes hyperactive and mischievous. However, there are times she's shown to be the wisdom of the house. She is voiced by Candi Milo.
- Duchess - A "high-maintenance" pedigree friend who is pompous, ugly, rude, arrogant, and lazy up to the points he orders Frankie to open her eyelids for her first thing in the morning. She considers herself superior to all the other imaginary friends, is extremely negative towards everyone, and never says anything nice (despite this, she has helped someone in four episodes, albeit for selfish reasons). Whenever Duchess turns on the spot, her entire body pivots like a sheet of paper being flipped, revealing that she is two-dimensional (however, in the pilot movie "House of Bloos", she was not two-dimensional). Her full name is "Her Royal Duchess Diamond Persnickety the First, Last, and Only". She is voiced by Grey DeLisle.
- Goo – A hyper-imaginative, hyper-talkative girl who first appeared in the episode "Go Goo Go". Her parents allowed her to name herself when she was a baby resulting in the full name "Goo Goo Ga Ga". Goo enjoys playing games such as Checkers and Truth or Dare, but she does not know how to play and Mac is the only one who notices. In her first appearance she constantly created friends because she had no real friends because of her odd behavior. She finally stopped making new friends after Mac told her to get to know the ones she had made already. However, she has still created a few by mistake or to help on rare occasions. She is also shown to be friends with Cheese, as both of them get along because of their odd doings. She looks a little older than Mac, though it's never been stated how old she is. She is voiced by Grey DeLisle.
- Terrence – Mac's 13-year-old brother and the primary villain of the series. He enjoys bullying Mac with his other 11,12,13 and 14 year old friends and coming up with various schemes to make Mac's life hard and miserable, usually trying to keep Mac and Bloo from seeing each other ever again. His stupidity always gets the better of him, making him easily outsmarted by Mac or Bloo. He is the one responsible for Mac's mother's decision of telling Mac he needs to get rid of Bloo, since she was tired of the three of them always fighting. He is voiced by Tara Strong.
- Cheese- A simple, pale-yellow-colored friend who debuted in "Mac Daddy". Cheese was thought to be an imaginary friend accidentally created by Mac, but was actually created by Mac's neighbor Louise. He appears to be somewhat wikt:madcaplmadcap and dim-witted, often saying incoherent or non-sequitur phrases, and breaking into sudden bouts of screaming when frightened or when he doesn't get his way. Cheese likes goldfish crackers, cereal, juice, chocolate milk ( although he is lactose-intolerant), and so on. In the series finale "Goodbye to Bloo", he becomes the newest resident at Foster's,, much to the other resident's surprise/horror. Cheese is always considered to be an annoyance, but is treated like a friend by Mac's friends in "Infernal Slumber". He is voiced by Candi Milo.
- Jackie Khones - A small, green imaginary friend who has only one eye. His main personality trait is that he is really fond of food, especially sandwiches. Jackie has been a supporting background character in the first 4 seasons, but he later had much more importance to the episodes in Seasons 5 and 6, even getting an episode centered around him, which was Season 6's "Jackie Khones and the Case of the Overdue Library Crook". Jackie is also very lazy, and usually asks other people to make him a sandwich. He seems to be the love interest of Fluffer Nutter, a pink, squirrel-like imaginary friend who seems to care for Jackie a little more than he does for her. Jackie is voiced by Phil LaMarr.
Foster's Home for Imaginary Friends was named the 85th best animated series by IGN, which called it very funny and endearing. Mike Pinsky, in a review on DVD Verdict, praised the art design and the characterizations, particularly singling out Cheese as possibly “the quintessence of Foster's surreal charm" in his season two review.
The show was nominated for four Annie Awards in 2004, and 5 more in 2005, winning two awards that year for Best Original Music in a Television Series (James L. Venable and Jennifer Kes Remington for "Duchess of Wails") and Production Design in an Animated TV Series (McCracken with Mike Moon, David Dunnet and Martin Ansolabehere for the Christmas episode "A Lost Claus"). Five more nominations came in 2006, with three wins as Best Animated Television Production, Best Original Music in a TV Series (Venable and Remington winning again for "One False Movie") and Production Design in a TV Series (Ansolabehere by himself for the one-hour "Good Wilt Hunting" episode). Venable and Remington teamed up for the show's lone Annie nominee in 2007, for their original music in a TV series for "The Bloo Superdude and the Magic Potato of Power". The show was able to garner 2 more nominations in 2009 for the categories Character Design in a Television Production and Production Design in a Television Production with the nominees being Janice Kubo and Ben Balistreri respectively.
The show has won a total of seven Emmy Awards. The episode "House of Bloo's" won two Emmy Awards for art direction (Mike Moon) and character design (Craig McCracken). "World Wide Wabbit" won an Emmy for best storyboard (Ed Baker). The show's theme song (described by McCracken as "psychedelic ragtime" and written by Venable) was nominated for Best TV Show Theme in 2005, but lost to Danny Elfman's theme to Desperate Housewives. The episode "Go Goo Go" was nominated for Best Animated Program Under One Hour in 2006, and Character Design supervisor Shannon Tindle won an Emmy that same year for that same episode. The 2006 episode "Good Wilt Hunting" was nominated in 2007 for Best Animated Program One Hour or Longer, but lost to the Camp Lazlo TV movie "Where's Lazlo?". However, David Dunnet won an Emmy for his background key design for said episode. The 2008 television movie"Destination Imagination" won another Emmy in 2009 for Best Animated Program One Hour or Longer. Copyright: http://en.wikipedia.org/wiki/Foster%27s_Home_For_Imaginary_Friends