He's pretty much a sadist that takes a downright disturbing amount of glee out of tormenting the contestants on the shows, both through torturous and sometimes life threatening challenges or just fucking with them inbetween them. It plays into the point that there's a lot of slapstick to the humor.

I'm not sure there's a single moment that the guy isn't laughing his ass off or has a large grin over someone being miserable, and it's like that for every season except the last one where they replaced him with a new character.

Evolved form of Satan at peak perfection