The 64th spirit of the Goetia. He is a great duke and appears at first as a mighty terrible and strong leopard but at the command of his summoner he assumes the shape of a man with fiery eyes and a terrible countenance. He can see the past and future, but unless he is commanded into a triangle he will lie in all those things. He will gladly talk of divinity and of the creation of the world, and of his and other spirits' falls from grace. He can control fire and burn all of his and his summoner's adversaries to death and will not suffer them to be tempted by any spirit or otherwise. He governs 36 legions of spirits.
Flauros makes his first and only non-Fallen appearance as an angel dubbed Flauros Hallel fighting alongside Chiaki Hayasaka after she has assumed the form of the Baal Avatar. There is no way to recruit this form of Flauros into the player's party.
Flauros' Fallen form, however, appears throughout the game, even before the aforementioned fight, as an enemy in random encounters.
Persona 3
"One of the 72 demons of the Goetia. He appears as a leopard and can see the past and future. He can control fire and burn all his adversaries to death."
—Persona 3 Compendium
Devil Survivor 2
"One of the 72 demons of the Goetia, appearing as a leopard-faced warrior. He has the power to see the past and future. He can also control fire and burn anything his summoner wishes."