I hate it when a photo is ALMOST good enough for an ID lol. It could be a columbellid, but the shoulders look pretty broad for that. Coronations are kind of unusual in the columbellid family, but there are a few species that have them, especially as subadults. So...it's probably either a columbellid, which is harmless, or it's one of the coral-eating snails in the Murex family. If it's a bad guy, the animal will be a pale greenish color.
Cheers,
Don