Bottom, is a leader of a troupe of clowns of a ragtag group of "actors" (term loosely used) bent on putting on a play. He is boisterous and comically serious, directing his players with the utmost sincerity but appears as ridiculous.
It is fitting that the fairy, Puck, turns him into an ass. His behavior is often asinine.
Bottom is often comic in his own failure to either lead or realize what an "ass" he is. Even when Puck's mischief has ended, Bottom is still the butt of the joke. For example, after he has been freed of his ears and tail, he wonders aloud:
"I have had a most / rare vision. I have had a dream, past the wit of / man to say what dream it was. Man is but an ass, / if he go about to expound this dream" (IV.i.204-07).
Still, even if he is ridiculous, he's a winning personality. He is full of humor and word play, and completely without malice.