Dionysus (Διόνυσος in Ancient Greek ) is the god of grape-harvest, wine, ritual madness and ecstasy as well as theater. He is also known as Mr. D, the camp director of Camp Half-Blood, a role he dislikes, and will perform his duties in a lazy manner while threatening campers with death regularly (normally by claiming to send out the harpies). His followers are satyrs who perform tasks for him such as locating demigods among other more menial things.
Dionysus was often called the ‘twice born’ because of the two myths around his birth. The most common is that his mother was a mortal woman named Semele, who was a daughter of the King of Thebes, and his father was Zeus. This makes him the only Olympian to have a mortal parent, and according to some traditions the only one to have been born a mortal.
As with most of Zeus’ acts of infidelity, Hera became jealous when she found out that Semele was pregnant with Zeus’ child. She disguised herself as a nurse (or old crone in some stories) and made Semele begin to doubt that it was truly Zeus. While in disguise; Hera convinced Semele to ask Zeus to reveal his true form, to make sure that he would do it, and to swear on the River Styx, which is sacred to the Greek Gods and an unbreakable oath. Zeus tried to get around the promise, but in the end swore on the River Styx, and Semele asked to see his true form. Unable to go back on the promise, he did so, and she was burned to ash. Zeus managed to save the infant, sewing him into his thigh until he was born a few months later as a full grown baby on Mount Pramnos in Ikaria. He was born a demigod, like Hercules and Perseus.
In his early life Zeus sent Dionysus off with Hermes. Again here, there are two versions of the story. In one version, Hermes took Dionysus to King Athamas and his wife Ino, who was Dionysus’ Aunt. Hermes had them raise Dionysus as a girl to hide him from Hera’s scorn. The second story is that the boy was taken to the rain nymphs of Nysa. They raised him through infancy and childhood, and in reward for their care, Zeus placed them as the Hyades in the stars. When he grew up, he discovered the vine, and extracted the juice. He was struck with madness by Hera at this point, and ended up wandering various parts of the world. Rhea cured him, and taught him her religious rites, and he wandered through Asia teaching about cultivating the vine.
He was very handsome as a young man, eager for challenges. Dionysus later said he was good at nothing in his human life but cultivating wine. The people in his village mocked him, not knowing of his heritage, of his father, or knowing his future, and what he would one day become. When Dionysus was invited late to the Mount Olympus, it was Hestia who graciously offered him her golden chair to prevent any conflict or embarrassment. Hestia was a goddess known for her warmth and kindness. Dionysus then rescued his mother from Hades, and she became a goddess on Mount Olympus, with the new name Thyone, presiding over the frenzy inspired by her son Dionysus. When Theseus abandoned Ariadne sleeping on Naxos, Dionysus found and married her. When she died, he went to the Underworld and rescued her, taking her up to Mount Olympus, where he made her immortal. He was disguised as a mortal on the seashore once, and a few sailors spotted him. They thought he was a prince, and tried to kidnap him and hold him for ransom or to sell into slavery. They tried to tie his hands behind his back, but no ropes would hold him to the pole. Some ideas are that the material they were made of then was similar to the vines, and would refuse to hold him. At this point Dionysus turned into a lion and let a bear loose on board. It killed those it came in contact with, and those who jumped off the ship were turned into dolphins as an act of mercy. The only one to survive was the helmsman Acoetes, who had recognized him as a god, and tried to stop his comrades from the beginning.
Dionysus has a chubby face, a red nose and curly hair so black, it looks purple. He normally has watery bloodshot eyes from drinking. He is usually described as wearing tiger-striped Hawaiian shirts and purple running shoes (even though he has never run once in his immortal life). He is described by Percy as a cherub who had grown up in a trailer park. Anyone can tell he’s no stranger to wine just by looking at him.
After chasing after an off-limits wood nymph twice, Zeus punished him by putting him in charge of Camp Half-Blood for 100 years. During this time, he is not allowed to drink wine (so instead swallows down several litres of Diet Coke) or grow wine grapes, even though he did use his powers on other plants such as strawberries. It is hinted that the first time he did caused the Prohibition era. After the war, Zeus decided to make Dionysus work at Camp Half-Blood for only fifty more years, as a reward.
He appears to have the fewest demigod children out of all the gods, not including the Big Three or the virgin goddesses- only having two sons, his twins, Pollux & Castor- possibly due to his hatred of heroes or his strong dedication to his immortal wife Ariadne on Olympus. He does care for his sons, as proven in The Battle of the Labyrinth & The Last Olympian when he is shown being depressed after the death of his son, Castor , and after becomes discreetly protective of his only remaining child, Pollux .
Dionysus enjoys calling people by incorrect names, and he often does this with campers who have been at camp for a long time. His hatred for heroes stems back to how Theseus abandoned Ariadne, and thus is why he has the fewest shown demigod children among the major gods.
Dionysus lets it be known he cares nothing for the campers, and does not ever show any fondness towards them. He is no kinder to Chiron, but never threatens him like he threatens the campers and he likes a good party.
However, despite the impression he tries to give, deep down, Dionysus cares about his campers quite a bit, and is willing to send help using his godly powers when a camper is in danger and desperately needs help.