The lady crab (Ovalipes ocellatus) is a crab that is usually found on sandy shallow water. Normally, a very difficult habitat to live in because of wave action and shifting sands. This animal escapes these dangers by burrowing just beneath the sand surface. As waves toss the sand around, it quickly shifts position and digs back underground. The lady crab looks different from other crabs. The claws are not large but sharp. Its legs are flat and paddle shaped. The crab grows 4" (10cm) wide. The lady crab is found from Cape Cod to Texas.

The lady crab has teeth known as frontal teeth on its shell found between the eyes. The teeth behind the eyes are called marginal teeth. The lady crab has three frontal teeth and five marginal teeth. (Each side; thus the lady crab has ten total teeth)

The lady crab will eat on live or decaying organisms such as fish, crabs, or clams which makes it a carnivore and scavenger. When fish or worms pass it, it comes out of the sand, and grabs the animal with its claw.

Like other swimming crabs, the lady crab has less protection than other crabs that have hard shells. The lady crab has an exoskeleton. For the lack of protection, it makes up for this by its speed and camouflage.

The lady crab has compound eyes set at the tips of the pair of stalks. Being that the eyes are at the tip of the stalks, it allows it to see more clearly. The eyes are stalked which allows them to be aware of predators.

Males and females are told apart by looking at the abdominal flap beneath their bodies. The female has a wide body to carry the eggs while the males have a thin flap. Once the eggs hatch, they're planktonic. When they are born, they do not resemble their parents until they have molted several times over the next few weeks. As they grow, they pass through two main stages called zoea and megalopa before being an adult.

The lady crab sheds, like most animals with exoskeleton, as they grow. They appear to stop shedding when they're 4" wide. Adults that stop shedding are usually covered in barnacles or seaweed.