Personally, Sully! In being a monster, who can beat HUGE, GIANT TEETH, LOUD ROAR and CLAWS AND HORNS!?! Randall is scary, but zaidi in life with a personality than being a monster. If I met Sully in my bedroom, I'd be scared to death and faint, if I met Randall, I'd probably hit him over the head with a tennis racket and say "OMG, BABY CROCODILE! I gotta call Wires!" Randall's just...a bad guy. Sully's scary.