The thin snake eel (Ophichthus apachus) is an eel in the family Ophichthidae. It was described by John E. McCosker and Richard Heinrich Rosenblatt in 1998. It is a marine, tropical eel known from the eastern central and southeastern Pacific Ocean, including Mexico and Colombia. It is known from two specimens observed dwelling in sand at a depth range of 0 to 8 m (0 to 26 ft). The maximum length recorded was 23.1 cm (9.1 in), albeit on an immature specimen.