Mike - If it is a Majano, Majano's are like the Tribbles from the infamous Star Trek episode... They're cute, and "easy to keep"... And soon... Cool! I've got another one! Wow! Now 4! About the time you get 8 you start to get concerned, next thing you know they're popping up all over the place taking over your tank...
Some people (Rather inscrupously IMHO) sell them on eBay... Some people like them, and they're not inherently "bad", they can just easily and rather quickly reproduce out of control...
(Note - This is all if the one on that snail is a Majano, I'm don't know if it is or not...)
Hope that helps...