Good Crab or Bad Crab???

[Murminator]

I bought a rock today to cycle my tank I dipped it in a pail with high SG to chase out any bristle worms, nothin but a few shrimpy things and a cute little crab I quickly put him in better water. He is about 1/2 inch across tan with tan/brown striped legs, botton of his claw look redish and long antenna's.
Is he good to put in my tank or bad
How bout the little shrimpy pod like things?

The crab has 24hrs................

MUUUHAHAHAHAHA