Compassnico said: Dunno how to translate こいつ. "This fellow" would sound ridiculous
You don't always have to do a literal word for word translation. When the literal translation would sound dumb, just try to think of the sort of tone that the added コイツ adds to the sentence, and try to think of an English equivalent. In this case, I thought it added a little harshness along with some disbelief to the sentence, so I went with "Cute as hell..."