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 心 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 野兔 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 由 Keith Ferguson.

We all 爱情 Bloo. He is the life of the show, the 果冻 on the 花生 牛油, 黄油 sandwhich, the sprinkles on the cupcake. Without him Foster's 首页 for Imaginary 老友记 would be nothing.