Peter

Pettigrew has no idea whatsoever how he's involved with the Marauders.

He doesn't have the guts to join in bullying the people Sirius and James bully - he doesn't have the guts to stand up for them, either. He isn't rebellious (Sirius). He doesn't calm the others down (Remus). He isn't clever, or funny, or the one girls fawn over, or witty, or brave (he doesn't understand how he 's in Gryffindor, either), or charming, or good looking.

People look at him in confusion when he's with his friends.

He doesn't belong.