I have a yellow watchman goby and he is really cool! He hangs out in his cave peaking out all day long! He likes to wait for hermits to walk by and pick them up and bring them into his cave, doesnt eat them he just takes them inside and drops them off???
I have 2 cleaner shrimp and they are really neat to watch cling onto my tangs and clean them. I think if you were to get peppermint shrimp in a 125 you probably wouldnt see them to often, I had a few in my 120 never really saw them unless i was looking in at night with a flashlight. Just my personal expierence, but I am a rookie still!