I found this snail on my zoas I pulled it of, anyone know what this is
Does it have a soft shell (or no shell) -- if so it's probably a Stomatella snail.
Stomatella | Melev's Reef
Many people ask about a snail or slug with a half-shell on its back. They are called Stomatella, and are fast moving slugs. Their shell is similar to a fingernail in shape, which covers the head and torso of the creature. They are found moving about the rockwork especially at night, and are an...www.melevsreef.com
Stomatella Snails
www.aquaticcommunity.com
Judging by the picture posted and that other above said already, it looks like a Stomatella. Have you removed it? Maybe snap a better picture with a white background, like in a bucket or container.