Grug appears to be a. . . special case.

Born to some strange pairing of a foreign variety of troll, and an Orcish warlords, they spawned Grug.  Grug isn't big. Nor does he look intimidating whatsoever, considering his extreme lack of, let's just say, "Orcish thugishness." But he's incredibly strong, far beyond what is reasonably possible due to his slight, curvy frame.  He carries around a stick that's his size, and can swing it around like nothing.  He loves swinging it around.

He's not very bright, nor is he that clean.  He bathes daily, but only with water, requiring anyone who might look after him to forcibly soap him up, to which he will be quite opposed to.

While he does attempt to portray himself as a powerful warrior, he finds himself fawning over bigger, masculine men. He'll often try to prove he's really strong to impress them.  He doesn't quite understand that they're usually more interested in his girlish frame.