Thank you all for reply.
It's not squilla empusa? But is it ok to set him(Snatchy) up a same tank environment as for squilla empusa? or is it different than squilla empusa? Right now he's in 12 gallon tank (crushed coral bed, some live rocks, 76~80 degree in temperature), seems too little for this 5" mantis but he is doing pretty well so far. He is swimming, digging, and hitting (stabbing) my hermit crab (Dumbo) when Dumbo gets close to him. It's pretty cool and fun to watch.

and also i have a Gonodactylaceus falcatus (Wimpy) in same tank. When Snatchy first added to the tank, Wimpy showed some curiousity but now he is hiding in his burrow and never comes out.

anyway sooner or later i will definitely get Snatchy a bigger tank and set him up a new environment just suitable for him but I just need to know some more informations about Snatchy's species.
by the way, sorry about the cheezy names. I just named them as how they act.
oh and i have another question...
how do you guys feed your mantis shrimps? is there any good sinking carnivore food? I bought 5 little hermit crabs for Wimpy's dinner but Wimpy doesn't eat those. Wimpy is too nice to eat live ones.

And is it ok to feed feeder gold fishes to Snatchy?