I think that he is a funny guy who thinks too much of him self. He is different from Theseus because is a plain and strict guy.
Bottom is an artisan who would be considered "middle class" in today's society (or the "working class"). Theseus is an aristocrat. He is the Duke of Athens. The aristocrats and artisans use different dialects and there are differences in their behaviors, obviously. Theseus is very logical and serious and is a good ruler. Bottom is very much a "clown" in that he loves to have attention showered on him. He loves to be the center of attention and believes he is a better actor than he is.
BOTTOM IS HILARIOUS. HE IS VERY FUNNY WHEN HE USES THE WRONG TERMS AND STUFF!!