a hitchhiker i'v never seen before

sounds like it might be the one featured in the photo on the right here, 2n'd photo down
http://www.ucmp.berkeley.edu/arthropoda/crustacea/malacostraca/eumalacostraca/royslist/

diverse2.jpg
 
no. the closest i can compare it to is a scooter blenny. it swam like one and i didnt notice all the legs along the body and instead of sharp colors it looked kind of like blurry stripes, again just like a scooter blenny.
 
so i did brine shrimp again to lure him out. its defineately the above mentioned mantis shrimp. i saw the hole he resides in and now i actually kind of like him. my next question is will he affect any corals or fish that i put in in the future? and will he stay small, or get big?
 
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