Dionysus, known as Bacchus to the Romans, wad the god of wine. He was considered on of the Twelve Olympians.
There are various accounts of his birth. One has him the result of the union of Zeus and Persephone. Dionysus was killed and dismembered by the titans but was rescued by Zeus and was attached to Zeus to be reborn. This dismemberment may be why some identified him with Osiris. Another has him as the son of Zeus and the mortal of Semele. Semele died while still pregnant with Dionysus. The fetus was attached to Zeus for the remainder of the pregnancy.
The draw for Mythicists is his strange birth, which is often described of as a virgin birth, but really is not. Also he is the god of wine and wine becomes central to the Christian sacrament of the eucharist.