Crab ID

[Idaknow15]

Appreciate the image isn’t the best but this is a reclusive little crab! He has been hiding out in some live rock and I’d like to know what he is before I decide if he goes in the main tank, the sump or go the LFS! I’m sure his little eyes looked red too if that makes any difference!

 

[blaxsun]

Looks like it may be a flat back mud crab. The consensus seems to be sump.