Zoathid predators?

look like sundial snails and yes they are zoa predators I got thems a few months ago and they did a good amount of damage to thems.

Those just look like some sort of algae grazer. They aren't the sundial snails I have seen unless they are some different species.

what are they exactly?

i got a zoa frag n there was like 4 little ones on it and they all scampered away

They arn't sundial snails.. looks like grazers