Crabs are passive land mobs that spawn in marine biomes. They are nice to look at, as they constantly walk sideways.
Crabs have 3 hearts, and will regularly scuttle among the beach sand and the seabed. They are skittish, and will flee into the water when they see a player. They are unable to swim, and will sink to the bottom of the ocean. However, they are impervious to drowning, and will not get slowed down by the water.