Proteus:
(From Wikipedia)

In Greek mythology, Proteus is an early sea-god, one of several deities whom Homer calls the "Old Man of the Sea"[1], whose name suggests the "first", as protogonos is the "primordial" or the "firstborn". He became the son of Poseidon in the Olympian theogony (Odyssey iv. 432), or of Nereus and Doris, or of Oceanus and a Naiad, and was made the herdsman of Poseidon's seals, the great bull seal at the center of the harem. He can foretell the future, but, in a mytheme familiar from several cultures, will change his shape to avoid having to; he will answer only to someone who is capable of capturing him. From this feature of Proteus comes the adjective protean, with the general meaning of "versatile", "mutable", "capable of assuming many forms": "Protean" has positive connotations of flexibility, versatility and adaptability.