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 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 is shown to have bad memory some of the time. He is voiced by Keith Ferguson.

We all love Bloo. He is the life of the show, the jelly on the peanut butter sandwhich, the sprinkles on the cupcake. Without him Foster's Home for Imaginary Friends would be nothing.

Mac:it is all about you and bloo :c.
Ian:i know this.
bloo:and it is about me!
Ian:yes bloo it is about you and me.
bloo:coooooooooooookieeeeeeeeeee!!
dede:what do you want!
bloo:cookieeeeee!
dede:go away!
bloo:i want cookieeeeeee!
dede:mac what is up with bloo.
mac:he LOVES cookies.
bloo:i want cookie!!!
Ian:see the cookie bloo FETCH!!!
dede:hey that was my only cookie
Ian:TO BAD!
dexter:mom wants you home.
dede:OK bye.
Ian:bye
mac:bye
bloo:bye
wilt:bye who ever you are
bloo:GET OUT OF THIS STORY!!
wilt:i am sorry bye
bloo:finnaly wilt is gone!

Ian:lets run!
bloo:ya!
mac:i told you that you should have not done that.
Ian:no you did not.
mac:ya i did.
Ian:no you did not.
mac:ya i did.
bloo:be quite you are right ian you are wrong mac!
mac:no!
bloo:ya!
mac:no!
bloo:ya!
ian:enough!!!
Ian:stop fighting!
bloo:y should i.
berry:ya y should he!
bloo:berry! stay out of this story!
berry:fine!!!
bloo:so as i was saying i do not have to be quite!
Ian:fine talk all you want!
Ian:i am leaving!
mac: no the whole story is about you!!!!!!
Ian:no it is all about you and bloo!
Mac:well look at the top it says ian&bloo.
Ian:COOL!
mac: it is about you and bloo i am not even in the title.
Ian: o ya look at that.