Charybdis natator has a fan shaped carapace which is brown to orange in colour on the dorsal surface the ventral surface is bluish mottled with white and pale red spots and the legs are dark, reddish brown in colour.

The carapace is densely covered with short pubescence which is absent on the distinct transverse granulated ridges in the anterior surface.

The last pair of legs are flattened and can be rotated in a propeller like manner allowing the crab to swim in any direction.

[2][3][4][5][6][7] Charybdis natator is found throughout the Indian and Pacific Oceans from eastern South Africa and Madagascar north to the Red Sea and across the Indian Ocean, including the Mascarene Islands and the Seychelles, to the western pacific where it extends north to Japan and south to northern Australia including Lord Howe Island.

[6] It was named as Cancer natator in 1794 by the German zoologist Johann Friedrich Wilhelm Herbst.