i copied this from another site.... i would put the link but dont want to get in trouble for it
AEOLID NUDIBRANCHS
There are lots of aeolids (including the aiptasia-eating berghia - a good guy to have!) but the most common one for us is this guy - a zoanthid predator! They are a pain to get rid of but will mow through your zos if you don't.
to me it looks almost like the pic that they posted of one that eats zoos