This is a statue of Serapis (Osiris), Roman, second century AD, found in Perge in 1957 (the torso) and 1968 (the head) in respectively the colonnaded street and near the Eastern Hellenistic Tower.

The very complicated story about how the Egyptian god Osiris, as Pluto known to the Greeks, and Asklepios, then Zeus came to the Roman world is too complicated to tell here. The statue shows him in a sitting Zeus-like attitude, wearing a cylindrical crown on his head, holding a sceptre in his left hand, a mythical animal, the Sphinx, sitting to his right.

Source: Sculptures of the Museum in Antalya