This may not be exactly a weird animal, but it definitely isn’t your average looking crab either. You can find these beautifully patterned crabs in the western Atlantic Ocean from the Chesapeake Bay to the Dominican Republic. It is no bigger than your local crabs, with a 3 in-wide carapace. It lives at depths of up to 151 ft on sandy and muddy substrates. It often carries the sea anemone Calliactis tricolor on its back, or lies buried in the sand, with only its eyes exposed. These crabs reproduce in the summer, and their eggs are carried by the female until they hatch.
There’s not much else to say about these crabs, other than the way they look, they’re not much different than your local common crab. Here’s an awesome video I found from user eastendsi of a Calico Crab he found on Sanibel Island Beach.