Well, the combination of angels and mollies is possible if there's enough swimming space. Mollies can be nippy as well. But most of the time they can handle another. And not all mollies are aggressive. Same goes for angels. It's more the individual nature of a specimen that's crucial. And aggression can be triggered when they have not that much swimming space. But again, just like guppies, mollies can nip at fins when they're irritated by other fish.emeraldking may be able to say something about the aggressiveness of mollies.