388 Charybdis (/kəˈrɪbdɪs/, prov. designation: A894 ED or 1894 BA) is a very large background asteroid, approximately 125 kilometers (78 miles) in diameter, that is located the outer region of the asteroid belt. It was discovered by French astronomer Auguste Charlois at the Nice Observatory on 7 March 1894. The carbonaceous C-type asteroid has a rotation period of 9.5 hours. It is probably named after Charybdis, a sea monster in Greek mythology.