I'm many things. I'm the voice in your head, the Dark One's powers inside you, inside all the Dark Ones. Rumplestiltskin is but one of many. Perhaps I can be another. How about Gorgon the Invincible?
Gorgon the Invincible is a minor character on Once Upon a Time. It is a former Dark One that was, or at least had to ability to look like a Bandersnatch who could breathe fire. It, along with all the other past Dark Ones join Nimue in Storybrooke where they plot to snuff out the light once and for all, but are ultimately defeated by Captain Hook, who sacrifices his life. However, what soon becomes apparent is that all of the power from Gorgon and the other Dark Ones was in fact transferred back into Rumplestiltskin, thus making Hook's sacrifice pointless.
Before the Curse
Everyone who steps from this well enjoys the taste too much. The only way to stop is to be stopped. This is the fate of all Dark Ones.
Gorgon was once either a fire breathing Bandersnatch or a person who had the ability to change into the appearance of a Bandersnatch. At some point Gorgon kills his preceding Dark One by stabbing him with the dagger, thus making him the Dark One. He goes on to become known as Gorgon the Invincible, but this turns out to be false as Zoso manages to come into possession of the dagger and stabs Gorgon with it, killing him, and passing on the Darkness. ("The Dark Swan"/"Nimue")
After the Second Curse
No! I'll never be like all of you! I'll never hurt the people I love, the people who love me.
The Darkness takes the form of Gorgon the Invincible. ("The Dark Swan")
After Emma appears from the Vault of the Dark One, the Darkness appears to her in the form of Rumplestiltskin to guide her down the path of evil. When Emma questions if he's real, he explains that he's the voice in her head and can take form of many dark ones. He suggests transforming into another, then changing himself into Gorgon the Invincible, a fire-breathing bandersnatch that Emma begs to stop. The Darkness settles on the form of Rumple, who decides that it's probably easier this way. While Emma tries to gain a sense of her surroundings, Rumple asks if she's ready to begin training to be the Dark One, telling her to think of him as her guide until she's learned to embrace her powers. "I will never embrace the darkness," Emma assures, but Rumple tells her that they all say that; everyone who sips from "this well" (the vault) enjoys the taste (of darkness) too much, and the only way to stop is to be stopped. This is the fate of all Dark Ones. Emma tries walking away from the vision, but it assures her that she can't, proceeding to appear magically in front of her. She tells the fake Rumple that she knows she's in the Enchanted Forest, which means Merlin can't be far from where she is and the Apprentice told her that he can destroy the darkness so she's going to find him. "Merlin? Oh, you're better off with me," Rumple tries, but Emma profusely protests, refusing to be like all the Dark Ones before her and hurt the people she loves; the people who, in turn, love her. She walks through the vision and continues on her quest. ("The Dark Swan")
After the Third Curse
We're here. All of us, as promised, in the flesh. And now it's time to get to work, to do what Dark Ones do best... snuff out the light.
Gorgon and the other Dark Ones witness the reforging of Excalibur. ("Nimue")
In Storybrooke, Emma now has both halves of Excalibur, as well as the means to unite them. Her vision of Rumplestiltskin points out that it's a thing of magnificence and asks her if she knows what the sword as a whole represents. She assumes power, but he tells her that it's history, adding that Excalibur's promise was forged long ago and that now it's finally going to come to fruition. He tells her that it's time and she wonders why he won't leave her alone, at which a new vision of Nimue appears and tells her that they couldn't; she says that Rumplestiltskin's eyes are fine to look through most days, but that she wanted to see this for herself. Soon enough, every single past Dark One, including Gorgon, appears to Emma via vision, encouraging her to repair the sword. Emma soon takes the ember from the Flame of Prometheus and retrieves the spark from within, compressing it into a ball of light which hangs in midair as she forces the two ends of Excalibur into it. Soon enough, the sword is complete, but Emma hesitates before going to pluck it from the air. She tells a confused Nimue that Merlin told her not to do exactly this when she was a little girl, at which the first Dark One points out that she's a woman now, and the Dark Swan is convinced the take the power when all the others chant for her to do so. She stands there, holding the complete Excalibur, her plan ready to unfold. ("Nimue")
The Dark Ones return. ("Broken Heart")
After dueling Rumplestiltskin, Hook, having remembered that he is a Dark One, now has what he needs in order to open a portal to the Underworld: the blood of a man who's been to hell and back. He dips his hook, which is doused in Gold's blood, into a pond in Storybrooke, causing a lot of mist to appear. A boat soon emerges from this mist, led by the Charon, and a myriad of cloaked figures are his passengers. Every single past Dark One - including Gorgon the Invincible - returning to the land of the living. Nimue, in her mask, is the first to exit the boat and approach land. Hook greets her as she reveals her green and scaly face, and she tells him that they're all there as promised, in the flesh. She adds that now it's time for them to get to work and do what Dark Ones do best, which is snuff out the light. Hook welcomes her to town, excited for this prospect. ("Broken Heart")
The Dark Ones take over town. ("Swan Song")
With the resurrected Dark Ones having been unleashed upon Storybrooke, including Gorgon the Invincible, each one of them marks a living victim to be dragged down to the Underworld in their stead, thereby ensuring them permanent places back in the land of the living. Marked victims include Regina and Robin, who are ambushed when confronting Zelena, Snow and Charming, who are ambushed near the latter's truck, six of the seven dwarfs, who are surrounded on Main Street, Henry Mills, who's personally gone after by Nimue, and Mr. Gold, the man who's been to Hell and back and who educates the others on what they're going to have to face. The Dark Ones continue to move through town, waiting for the moon to reach its peak, for that's when the Charon will arrive on his ferry to take the marked victims down to the Underworld. When the time comes, everyone is teleported to the pond, and the Dark Ones wait patiently for it to happen. However, Hook's change of heart ruins everything for them, because he absorbs them into Excalibur and then has Emma strike him down with it, destroying both him and the darkness. It is later learned that the darkness wasn't destroyed though, having been redirected into Mr. Gold, who now possesses the combined power of every past Dark One. ("Swan Song")