i think he is neither, king boo is just a ghost caught between the worlds of living and dead, and he just wants to be left alone with his ghostly counterparts, and that's why he plays tricks on mario. to get him out of boo's house. you can't really say boo is a bad guy for that. they will, on occasion, play friendly sporting events as well as Board Games. you might say he's mario's frienemy. ill also tell you how to kill a boo one day.
good guy
good guy
a great guy
sometimes in games he is like in mario party 3 but in mario kart he's good just a guy driving a cart
Bad
bad guy
Yes. Bowser is the hero of the entire Mario series. He is a gentle, peace-loving dragon-turtle whose existence is plagued by a violent, evil plumber named Mario. NO! Bowser is most definitely the BAD guy!
Good guy with good intentions but bad ideas.
he is the bad guy in ghost rider
I Don't See him he do good or bad
Good guy
a good guy