Trope-a-Day: Giant Enemy Crabs
Giant Enemy Crabs: The tennoa are merely crablike – radially symmetrical, for a start – and breathe chlorine, but since their obligate utilitarianism puts them at odds with the rest of the Worlds at predictably regular intervals, well, they can play this one pretty straight sometimes even so.
Most of the crab-bots are pretty chill, though.