Commodus, AE18 of Corinth. AD 182-184.

IMP M AVR COMO ANTON AVG, laureate head right.
C L I COR, Poseidon seated 1eft, holding dolphin, and resting on trident.

BMC 632 (this coin); Paris 953; SNG Cop 355 corr. (obv. legend); Prowe II, 1054.

Image from BMC Corinth.