TV show that was on Cartoon Network. I dunno if they still air it, but it was pretty popular so they probably do, though I don't think they're making new episodes. Centered around a kid named Mac who is forced to give up his Imaginary friend, Bloo, but comes to an arrangement with Mrs. Foster who owns the 'Home' so that Bloo won't get adopted by a new kid, so long as Mac promises to visit every day. Bloo's a megalomaniac, so mayhem ensues. It was witty, retro at times and a lot of fun. Plus some nice character designs: