For 10 points, identify this son of Zeus and Semele, the Greek god of wine.
This figure supposedly fulfilled a promise to Prosymnus by sodomizing himself on that man's tomb. Often identified with the Phrygian horseman Sabazios and the Orphic Zagreus, he was the dedicatee of hymns called dithyrambs. He was once captured by pirates but escaped by turning them into dolphins, and he and his followers were once imprisoned by Lycurgus. Hestia gave up her throne on Olympus to him, and he was reborn out of his father's thigh after his mother saw his father in his full splendor. For 10 points, identify this son of Zeus and Semele, the Greek god of wine.
This figure supposedly fulfilled a promise to Prosymnus by sodomizing himself on that man's tomb.
{Dionysus} [accept Bacchus or Oeneus]