It looks like a wolf snail. They are native predatory snails that eat other snails. I went on thorough search, and learned lots of interesting things about some exotic snails, to figure out there identity earlier this year. I found two of them beginning to mate, but when I moved the pot that they were on to get a better photo oppurtunity they shied away from the disturbance.

My wolf snail pics

Here is a link that might be useful: Wolf Snail