Trash King is the antagonist of the story. He is forcing people out of their homes with his hole drivers and is stopping BK from saving his friends. He basically runs the entire town and sits on his own thrown of trash. Trash King is very stinky. He constantly has his hand inside of a pickle jar grabbing 1 big pickle he can't seem to get out, but tries to play it off as an inspiration thing, but he's just an idiot. He is like a young CEO of a business whose dad gave it to him, he doesn't really know what he's doing but knows he can butter people up with promises of power and uses that to his advantage when trying to win over BK. 

Trash King should sound like an young buffoon CEO who is really confident in himself but has nothing to back himself up with that. The closest I can think to this is someone like Zapp Brannigan, don't use his voice exactly but use it as an inspiration for this character. He should sound like he is brimming with confidence to try and pave over any mistake he makes.