Flourscent Green Lobster

[Van down by the river]

Reef_Raf nailed it, It's harmless Zulu.

Although a few species can be 5-8cm, most are under 3cm. As they have poor eyesight, and some are blind, they tend to be reclusive and shy. No bold cleaners in this family!

In the wild they are found within sponges, ascidians, corals and sandy/muddy/rubble bottoms often found living comensally with gobies. They excavate the burrow while the goby maintains "watch", the shrimp always keeping it's antennae touching the goby for any sign of danger.Occasionally I have found them on good live rock. Apart from the snapping sound occasionally made(mine loves to snap early in the morning,or whenever someone tries to "borrow" his burrow), they are harmless. They will also co-habitate with commensal coral crabs as well. There is between 550 and 600 species so exact id is probably not possible.

If yours is unwanted I will glady offer him a new home!!