Juan is a friend of Juse the girls meet in the WGA comic. He (perhaps with sarcasm) tells his four friends that they should help the girls out.

He and the rest of the Lobos meet a comeuppance when they take on the witches.

After seeing Lucy turn hat Lobo into a cockroach, he begs for mercy, so she turns him into a frog instead of a bug. He then proceeds to think like a frog and eat his friend.

His fate afterward is not known. Lucinda is able to leave her Alterations permanent. While able to say "shut up" as a frog, his mind seems to be gradually shifting to that of a frog's since he ate his friend. His friend laughing at him does not seem like adequate provocation to consume him.