Hecate or Hekat was a popular chthonic goddess, possibly originating among the Carians of Anatolia; the region where most theophoric names invoking Hecate, such as Hecataeus or Hecatomnus, progenitor of Mausollus, are attested, and where Hecate remained a great goddess into historical times, at her unrivaled cult site in Lagina. While many researchers favor the idea that she has Anatolian origins, it has been argued that Hecate must have been a Greek goddess. The earliest inscription is found in late archaic Miletus, close to Caria, where Hecate is a protector of entrances.
She has been associated with childbirth, nurturing the young, gates and walls, doorways, crossroads, magic, lunar lore, torches and dogs. In Ptolemaic Alexandria and elsewhere during the Hellenistic period, she appears as a three-faced goddess associated with ghosts, witchcraft and curses.
Hecate rules over the Mazurka Corridor. A thief known as Gaia is attempting to kill her, and has even stolen the Silver Relief, an item needed to progress through the dungeon. When Nakajima first battles Hecate she's unseeable, but if Nakajima has the Statue of Latos, Hecate will be rendered visible. After the triumph over Hecate, the Orb of Resolve is found and Latos' Statue will shatter.
Shin Megami Tensei II
Hecate is a boss that can only be defeated if she is encountered during the New Moon. If the party encounters her in any other phase, she will force the party out of the room.
Shin Megami Tensei IMAGINE
Hecate can only be acquired through triple fusion, but does not require a plug-in. She appears as a field boss that can be spawned close to in-game midnight in Ueno by approaching a statue in the plasma field next to Souhonzan. She also appears within the Ueno Mirage gold-level instance, a mob within Ikebukuro's Zoushigiya Cemetary, a mob within the Second Home instance, and alongside Nyx when she acts as a boss during the new moon phase in Shinagawa's ice caverns.
Devil Summoner: Soul Hackers
While not seen directly, Hecate is referenced through the spell "Full Moon Queen,” which unleashes her power to inflict Almighty damage to all demons. During a full moon, it is at full power, making it stronger than Megidolaon; at any other phase it deals only half damage.
Devil Survivor 2
"The goddess of the underworld in Greek lore. It is said she may be the deification of Queen Persephone's strict personality. Her duty sees the dead and those who incur the wrath of gods suffer by her extremely cruel hands. She is master of the Furies, goddesses of revenge. Her name means "she who acts from afar," and is associated with the moon. Later, when she was turned into a demon, she began to be depicted as having three heads: a dog's, a lion's and a horse's."
—Devil Survivor 2 compendium
Persona 5
"A Greek goddess of crossroads, ghosts and witchcraft, she is commonly attended to by dogs. She is also known to be the chief of the witches that appears in the play "Macbeth"."
I'm the Tyrant Hecate. Now, how should I torture our enemies…? Hee hee hee.
If you want a taste of real cruelty again, call me. Hee hee hee…
Gallery
Hecate in Kyūyaku Megami Tensei
Hecate's sprite in Shin Megami Tensei: if...
Model in Shin Megami Tensei IMAGINE
Hecate's sprite in Last BIble III
Hecate as she appears in Devil Survivor 2
Hecate as she appears in Persona 5
Concept art in Persona 5
Trivia
Hecate's profile in Persona 5 specifically mentions her role in Shakespeare's play Macbeth as the queen of the three witches who vaguely foretold the fate of the titular protagonist. However, many scholars contest that Hecate was not the character in Shakespeare's original script but added by someone else when the play was included in the First Folio.