(Rhett may be a wimp, but Ali is so gullible in that episode, he'd probably bluff his way to victory, and if it came to strength, I'm sure he'd win. Simply being chased around by a crocodile and a bird doesn't make you tougher.)
Big Daddy. He's tough for his size.
Topsy/Mr. Threehorn vs. Kosh/ Mr. Clubtail.