Good crab claw or bad?

[modom1207]

I’m having trouble identifying a hitch hiker on some live rock that has evaded my bottle traps for two weeks now. It’s never come out of its hole in the rock so I haven’t seen anything but its claws and its legs and a brief glimpse of its underside. The claws are a red-brown color that turn into gradient white tips. The legs seem to alternate between brown and red. The apron appears white, but I might be wrong on that. Everyone tells me to look at the claws to determine if they’re “needles” or “spoons,” but all claws look the same to me in pictures. I have no idea how to differentiate between the two. Can anyone with a better eye than I please help ID if it might be friendly or foe based on the claws alone? lol

 

[diverjm]

It’s really hard to tell but a good sign is the claw tips aren’t black. That is usually a tall tell sign that it’s an unwanted crab.

 

[plumbdogmillionaire]

I’m no expert and it’s hard to see it well in the pic but it looks like a claw made for crushing. Common sense makes me think that’s not good.