A pity I don't remember much about this. I'm fairly certain I saw at least one of the episodes. I guess by default, Cuntilda would be my favorite too. This seems to be made in the style of your Arfenhouse fanart. I love that semi-CGI feel it has. Or maybe it's more realistic stuff.
They remind me of Mandy from "The Grim Adventures Of Billy and Mandy". I think it's because they have no noses and they're mean girls. Not mentioning that movie here. They seem to be genuinely frightening. That must have been the intention.