I like your take on the Lauch Ness Monster, or however his name is spelled. As for the guy, his head looks like it's set too far back, like his neck doesn't bend back when his head does; I can see his neck curving into his face.
His arms and his head are at a different perspective than the rest of his body; they're set back further and angled toward the viewer than the rest of his body is. And his right forearm is angled toward the viewer more than everything else; his knife appears out place in his hand because it's fitting the same perspective as his arms and head are.
His leg also just juts out of his body in a weird way, it sorta looks like it's a fake limb. It would have been better if you hadn't drawn his leg there at all.
He also appears to be looking at the floor and not at the monster. If you distanced them apart more it would work in that aspect.