Cerberus is a giant-sized three-headed hellhound with glowing red eyes Its features resemble those of a Doberman Pinscher. It is known for killing humans. When dead, the body vanishes in a cloud of black smoke.
Cerberus is a three-headed beast from the Underworld that Hercules has to defeat to finish his Twelfth Labor. Before Hercules can confront the hellhound in the Enchanted Forest, he runs into Megara, who is running away from it. He urges her to keep running, while he stays to fight Cerberus. During the battle, Hercules goes for one of Cerberus' heads, but he is unable to fend himself from the two other attacking heads. He is eventually killed by Cerberus, who goes on to chase down Megara and kill her as well. Both Hercules and Megara, left with unfinished business because of how they died, end up in the Underworld. ("Labor of Love")
In the Underworld's underground prison, Megara remains trapped, unable to escape because Cerberus keeps a watchful eye on her. Another prisoner, Hook, convinces her to break out with him, but as soon as they begin making their way through the tunnels, Cerberus' roar warns them that they are being pursued. Before they are cornered, Hook allows Megara to flee on her own, telling her to find Emma once she gets out. Hook is left to fight off Cerberus, who slashes him several times on his neck, and he's saved only when Hades takes him away to his lair. Cerberus continues to stalk Megara, finding her in the woods, but Emma manages to teleport herself, Megara and Regina away before the hellhound reaches them. Mary Margaret enlists Hercules' help to kill Cerberus, in the hopes of finding Hook, as well as clear away Hercules' unfinished business. With Emma, Regina and Mary Margaret, Hercules enters the mines to look for the beast, eventually venturing deeper in by himself. Coming face-to-face with the glowing eyes of the three-headed dog, Hercules becomes terrified and runs back to his party. The group, hearing Cerberus quickly approaching, prepare to attack, only for Hades to call off his pet. From Hades, Mary Margaret learns of Hercules' greatest shame, that he died fighting Cerberus. Later, she asks for details about the battle, in order to figure out why he lost in the first place. When Hercules admits the two other heads of Cerberus were too much for him, Mary Margaret realizes he needs two other people to kill the creature. Cerberus, tracking Megara to an apartment, slams into the building seconds before she escapes. Joined by Hercules and Mary Margaret, Megara teams up with them, with each person taking out one of Cerberus' heads. After all heads are incapacitated, Cerberus dies, dissolving into black dust. ("Labor of Love")
|Once Upon a Time: Season Five|
|"The Dark Swan":||"The Price":||"Siege Perilous":||"The Broken Kingdom":||"Dreamcatcher":||"The Bear and the Bow":||"Nimue":||"Birth":||"The Bear King":||"Broken Heart":||"Swan Song":|
|"Souls of the Departed":||"Labor of Love":||"Devil's Due":||"The Brothers Jones":||"Our Decay":||"Her Handsome Hero":||"Ruby Slippers":||"Sisters":||"Firebird":||"Last Rites":||"Only You":||"An Untold Story":|
|Once Upon a Time: Specials|
|"Magic is Coming":||"The Price of Magic":||"Journey to Neverland":||"Wicked is Coming":||"Storybrooke Has Frozen Over":|
|"Secrets of Storybrooke":||"Dark Swan Rises":||"Evil Reigns Once More":||"The Final Battle Begins":|
Note: "Archive" denotes archive footage.