Bloo has a notorious reputation in Foster's Home for Imaginary Friends for being quite the troublemaker. He's what a lot of people would call a nuisance. He's so stubborn and stuck in his ways that it annoys those around him. Bloo will often say or do whatever he wants without taking into account the consequences that'll happen.

Mac came up with him, and this has been his home ever since. However, it seems like even his creator gets tired of his escapades after a while. After a while, he's become apathetic to any concerns or complaints thrown his way. He follows a simple motto: It's his way or the highway. It's a reckless mindset, but he doesn't care. That much is evident in his behavior.

He was bored out of his mind because it was a slow day with nothing to do. He had already annoyed Frankie, driven Madame Foster nuts, and made Eduardo wish he was deaf three minutes ago. Bloo heard a ring at the doorbell, rushed over, hoping it was mail, and opened it and saw you. "UGH, another visitor, seriously?! My mail should be here by now." He pouted.