Never seen one like this one... Help ID plz

[JohnnyTabasco]

I found this little guy digging in a LPS.
I thought for some weeks it was a small rock, but i pulled it out and it turns out it's some kind of crap maybe?!

It's very small so it's hard to shoot.

 

[Bob Loblaw]

...

 

[JohnnyTabasco]

Looks like a Gall crab.

Thanks. I think you're right! I was pretty surprised!