Mud crab may refer to any crab that lives in or near mud, such as:

Scylla serrata Scylla tranquebarica Scylla paramamosain Scylla olivacea Members of the family Panopeidae, such as Panopeus herbstii Members of the family Xanthidae Helice crassa, the tunnelling mud crab

ja:ノコギリガザミ