Thick skin doesnt stop katanas
bob has very good reaction time and can hold his breath for a while and has thick skin that can survive preasure He'll be able to do it
the "Shoulder" and "Knee" of the crabs have 270 degree rotation anyways. so trying to tie them up without getting stabbed is hard
Bob is not a human. YOu CaNt DiVe into a trench and beat up some angry lobster crab starfish with katanas for legs in there OwN tErRiToRy and not get a single cut from katanas who are silicon based life forms, while carrying a rope to tie them down, in a colony full of them. And he is one person.
bob has very thick and strong skin and can dodge the space lobster crabs
bob will tie up your aliens "arms" and itll be deffenceless
assuming he doesnt get crushed by water pressure
and get speared by a dozen angry lobster crab starfish that glow and have katanas for legs.