1. disseminating one's infection of crabs amongst a small group of people generally through participating in a Bacchanal orgy.
2. figuratively one who is involved in an overabundance of screwing and/or engaging one's member in that of a lower social caste.
Thomas: "I heard that Michael partook of the optional employee debauch last night."
Richard: " That is also what I heard."
Harrison: "Yes, he was the crustacean transportation."
"William, I don't mind you screwing around, but when it's with 7 other men at the same time, you're basically a crustacean transportation."
"Patrick, you need to understand that I want to be in that position."
"You might as well start barking because you are definitely sounding like a bitch."