Mac's 5-year-old imaginary friend and best friend who resembles a simple, domed cylinder. Bloo is sometimes self-centered, egotistic and narcissistic almost to the point of psychotic delusion and has a knack for getting into trouble. However, he still has a good tim, trái tim 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 thỏ rừng, hare Down"). His full name is "Blooregard Q. Kazoo". He became increasingly mischievous over the run over the series and is shown to have bad memory some of the time. He is voiced bởi Keith Ferguson.

We all tình yêu Bloo. He is the life of the show, the thạch, sữa ong chúa on the đậu phụng, đậu phộng bơ sandwhich, the sprinkles on the cupcake. Without him Foster's trang chủ for Imaginary Những người bạn would be nothing.