Mac is a good boy- bright, sensitive, and a little shy. His mother insists he's too old to have an imaginary friend. She means well, but Mac and his imaginary friend Bloo refuse to part. So Mac secretly brings Bloo to Foster's, where many other colorful imaginary friends live because their creators gave them up. The other friends are hoping to be adopted by a new kid, but Madame Foster, for whom the home is named, agrees to a deal with Mac that as long as he visits Bloo every day, Bloo will always be his and no other child will ever be able to adopt him. So now Bloo has a new home, makes new friends, gets into new mischief, and still sees his best buddy Mac every day.
I love this cartoon! It's so funny, even by adult standards. I don't know why potty humor is considered a factor here, because it really isn't. There might be a total of five or six "suggestive" comments in the entire series, they are all very mild, and should go right over the heads of anyone under the age of 8 or 9 anyway. And it does handle lessons and morals like friendship, loyalty, courage, peer pressure, self esteem, and others. On TV it's rated Y7, probably because some younger kids might find some of the imaginary friends a little scary looking, particularly the "Extremesaurs", but they don't make very many appearances. But even if some of the friends are "monsters", you can't find any funnier or nicer, other than maybe in puppet form.