I bought a purple lobster here. The only reason he is interesting is because I keep harassing him by moving his rocks. I can only do this because the tank doesnt have a lot of LR. I show him off to my young nieces whenever they come over for a visit. The animal sits all day and does nothing ....until the lights go out. Then he is almost KING of this new tank....takes what he wants whenever. All lobsters are omnivorous and will eat whatever is available....
As we all deliciously know, lobsters start small and grow big!
I personally would not put one into a coral tank because even if they don't eat your favorite specimens, you never get to see em unless you are extremely patient with a pen light.
just my opinion.