One of the three monsters Exdeath sent to stop us gathering the tablets.
Also this is our first explicit sign that Exdeath intends to create a world of monsters, rather than destroying everything just because. It makes sense, but also it could have gone either way given his wacky over-the-top villain persona. It doesn't look like we'll be given much indication that there is a sympathetic motive in the monsters wanting a world for themselves, either; they're just evil and want to take over reality. Fair enough.
Unfortunately, this guy chose the wrong stop to ambush us.
Leviathan emerges from behind the waterfall and promptly eats the guy.
"Monster general shows up to gloat at us and tries to kill us, Leviathan does a big stretch and casually paws him into oblivion" is just such a funny twist on this scenario, I love it. Dude really thought he had a moment there, and in the end we'll never know either his name or his combat sprite! Get punked!