My friend who has a reef used to talk about this black hitcher he had in his reef tank with very hairy legs and huge claws and how he was really afraid of it. Well, he passed an orange encrusting monti on to me about 8 months ago, and I guess the little guy took a ride to my house. Its about 4.5" across now and looks mean as mean can be, however I have watched it and its harmless. Still spooks me when I get to probing around my tank with a flash light at night and come across it though. Aside from that I think I have two hitcher crabs living in a cauliflower and another half dozen in various acropora and montis. So they are not always all bad.
Here's to swimmin with bowlegged women.
Reef with 30G Sump/Fuge Combo
-30G LTAnemonarium with mated porcelain crabs, 10 sexy shrimp, and 2 pink skunks all tied into the other 135G in my system.