This is my 10 gal bare bottom with betta, Steve, and 4 snails.
The croc is one that is connected to an airpump and the mouth opens and closes. Every now and then a snail will go inside to clean and it looks like he getting chewed up.
Here he is, deep in the croc's mouth,

He is trying to come out without being chewed up,

Hurry, hurry the jaws are coming down,

Sorry, I had a slow day!