Before cutscene: He's got funky socks, but he's still an ugly green creature. During cutscene: Half way up the wall is maybe not a naturally tenable position for a goblin. After cutscene: More like a goblin cooked.
The Goblin Cook, whose name is Mudknuckles, is a goblin chef who works in the kitchen in the Goblin Village. He is always experimenting and blowing things up in his kitchen, hence his frequent blackened appearance. When he is first met, he has just invented 'fast food', which is completely burned food delivered quickly through an explosion and the cauldron being launched in the air, arriving speedily at its destination (and likely destroying it).