Mean Pete had a fallout with Mean Mikey early on, and in this argument, he discarded his hoodie, revealing unique tattoos his real self doesn't share, and a plain black tshirt. Due to this argument, he stays by himself, usually hanging in trees to watching whatever happens below him.
He likes to lead others astray, in a way that almost seems like he is trying to help and be nice, indeed the kindness of his real self shines through, however in the end, he is giving wrong directions and instructions, so no matter how nice he sounds, he's a liar.
He's also a pickpocket, but not in the traditional sense, he doesn't just steal money from ponies. He gives ponies autographs for a very cheap price, claiming they will be worth much more on the secondhand market, but this is false, as no matter how similar he is to the original, his signature is different enough to count as forgery.
What does a clone who just hangs out in the deep woods need money for? Nothing, but he likes to hoard it as he knows it bothers ponies who could make use of it, he doesn't share.