Fiddler crab? In the sand at the base of a mangrove tree
Phylum: Arthropoda
Class: Malacostraca
Order: Decapoda
Family: Sesarmidae
Genus: Armases
Species: cinereum (Squareback Marsh Crab)
sorry for the awkward placement, didn't realize until after that it looked like they're attached to each other. they are not lol