If it is a "smasher" meaning you have been hearing popping or clicking/snapping noises in your tank, it whips out it's little hammer claw things to "smash" stuff at high speed. I had one it QT about 1 1/2 inch long - if I placed a piece of rigid aquarium tubing in front of it, the critter would eyeball it (you can see their beady eyes tracking it) and then it would go "SNAP!" and snap it, my wife just about jumped out of her socks when it did this, because she was very close to the QT when I was showing her.
Very large smasher mantises can smash so hard that they can blow out tank glass supposedly, but I do not know how frequently you will see a big one like that.
Divers call them thumbsplitters because if a big one snaps you then.........ow.
If it is one with little razor claw things (I have never seen one of those) I have read that they can give you little cuts and stuff if you happen to get them in a bad spot or you are handling them, etc.
So anyway just a pair of gloves and try not to get snapped or poked, they are intelligent and tough creatures IMO
but just treat them kinda like you'd treat a bee, just keep back a little bit and don't try to cuddle with it.
I wouldn't worry about it too much.
I talked with the President of liverocks.com who is a very nice guy who has seen a heck of a lot of mantises and he actually keeps a few of them, he says they don't deserve the "rip your arm off" reputation, he actually was hand feeding a large female until a fish ate it (the shrimp)