interesting question! da quello che ho visto online non sembra che sia stato coniato un equivalente in italiano, anche perche' l'uso che ne fa Smith e' molto personale. se, come affermano nei link, sta per 'scavenger', l'uso comune suggerirebbe 'jackal' o 'hyena', non 'lobster'. bello comunque
1. "Smith deeply resented Mekas for taking his film "with the position of defending it and yet essentially kicking it to death." Smith began calling Mekas names and Lobster was one of them. Lobsterism became a symbol for the exploitation, capitalism, being a scavenger, or taking everything for yourself. The lobster symbol apparently pops up alot in Smith's works."
2."Ultimately, Mekas was called a “lobster” by Smith, symbolizing a scavenger who takes what he needs to profit off a situation."