Let's see. Let me title this response "Lobster Homicides"
1) Damsel - $3.99 DEAD
2) Damsel - $3.99 DEAD
3) False Percula - $14.99 DEAD
4) False Percula - $14.99 DEAD
5) Mandarin - $19.99 DEAD
The Lobster is really cool looking. I hand feed this guy, and probably will never give him up. Really hardy, withstood many drunk re-aquascaping episodes. He virtually murdered every fish in my tank, except for one. I had a 3" Naso in my tank for a few weeks and the Lobster didn't lay a claw on him.
Put it this way. Make sure the fish in your tank are either the same size, or LARGER than the Lobster. He will pick on fish smaller than him. He never picks on my Zebra Hermits, gets along fine with my Fire Shrimp (although they remain on different sides of the tank.)
My advice is this, add the Lobster LAST. This way he will not have a chance to claim his "territory", and might likely be less aggresive towards his existing tank-mates.
Justin