Thinking lots about fiddler crabs.
The male’s large claw can account for half of their weight.
It’s very powerful and could kill other fiddler crabs, but most of the time confrontations end with the crabs waving their claws at each other and one leaving.

Stay back

Female fiddler crabs just have two small claws. The large claw of the male cannot be used for eating, they pick small bits of plant matter and detritus from the floor as they walk along with the small claw, and subsequently females can eat twice as fast as males.

There are over 100 species of fiddler crab.
The marsh fiddler crab, Uca pugnax has one of the most impressive looking claws I could find.