It was $2.99 + snails tax :)
Anyway, I got it home, acclimated it then introduced it to Jack Skellington, Zero and Dr. Zoidberg.
Went back a little later and could not find it. Panic! Looked all over, the only place it could have gone was to the interior ceiling of 'the crypt', UNLESS the mysteriousness is it can either camouflage itself perfectly into it's surroundings, or it can literally make itself invisible, or it warps in and out of dimensions.
Or the mystery is, it's not really a snail.
It's an alien.
Just checked and it's back from wherever it was.
Maybe space, like Helldin's Schnecke :) Maybe it, too, is a Slime Lord :)
So here are some photos (sorry, they aren't very good. I had the camera too close. There is now a video at the end of this post.)