As a cursed womb, Dagon had a red octopus-like head with the tips of the tentacles being black, along with two black lines above the tips. Dagon has large muscular arms with four fingers, a caterpillar like body, and wears a white cloth over itself. Dagon could not speak during this time and simply emitted odd noises.
As a cursed spirit, Dagon has a red octopus-like head with black dots on the top, red muscular shoulders and arms with sections of the arms, thighs, hips and upper chest being tan, a black midsection, red legs with tan parts, and a pair of red and black wings on its lower back.
Due to Dagon's short time as a fully-fledged cursed spirit, not much is known about his personality. As a cursed womb, he didn't show any defining characteristics other than obedience consistent with a teammate.
When Dagon developed into a cursed spirit and began engaging sorcerers during the Shibuya Incident, he was shown to be just as ruthless and spiteful against humans similar to both Mahito and Jogo. He also appears to be quite arrogant about his abilities, as he expressed surprise at the sorcerer's power at being able to damage him after being evade his attacks for so long. However he did display some tactical wit as he held his own against three fine sorcerers in addition to figuring out their strategy.
Later Dagon uses his Domain Expansion within an apartment, and relaxes in the water while Mahito sits on the beach. When Geto arrives, he comments about how Dagon has quite the calm domain.
Before October 31, Dagon is playing with Hanami and Mahito while Geto and Jogo discuss their plan to seal Gojo.
On October 31, Dagon is with Geto while Hanami, Jogo, and Choso deal with Gojo. Once Gojo is sealed, Dagon joins the others. When it is revealed that Gojo has been sealed and that shamans would be coming to their location, Dagon joins in when they decide to combat the shamans. Before splitting up, Dagon eats a large amount of humans.
Dagon is waiting behind a pillar when he runs into Nanami, Maki, and Naobito. Naobito easily manages to capture Dagon and lands a devastating blow that forces Dagon to throw up a large amount of skeletons. Dagon starts to remember his friends but becomes angry when he remembers Hanami, and says that he will kill them for what they did to Hanami. Dagon then shed its skin and becomes a fully manifested cursed spirit. Dagon releases a large amount of water but the three manage to withstand the attack. Naobito starts to ramble on about frame rates in animation sequences, which Dagon ignores and comments about how he and his allies have names when Naobito refers to Dagon as "cursed spirit".
Dagon is then attacked by all three, and Dagon manages to defend itself by creating a water barrier. The three start to rush Dagon down with speed, which forces Dagon to retreat. Naobito manages to overwhelm Dagon, and Dagon notices that he can't use his technique because of Naobito's attacks. Dagon then manages to trap all three within its Domain Expansion. Dagon tests the three with his sure-hit technique and figures out which to take out first. Dagon uses it's Death Swarm attack to take out Nanami first and block Naobito's view. While Naobito's view is blocked, Dagon delivers a blow that sends Naobito flying and then swarms him with shikigami. Dagon attacks Maki with a kick, while also proclaiming that she is the weakest. Maki returns and comments about how Dagon should have killed her with one attack, which Dagon decides to attack her like he did with the other two. Dagon is then shocked when Megumi breaks into his territory and delivers Maki the special grade cursed tool: Roaming Cloud.
Dagon tries to attack Megumi but Maki wounds Dagon with Roaming Cloud. Dagon tries to use his domain's technique but notices that Megumi is blocking him from using his domain's technique. Dagon tries to attack Megumi, but Nanami, having survived the Death Swarm, comes to protect Megumi. Maki and Naobito then attack Dagon, and Dagon protects himself by using shikigami. When Nanami tells Maki and Naobito to "assemble", Dagon figures out their plan and chases after them. When Toji enters the Domain, Dagon thinks that that was their plan all along. As Toji prepares to fight Dagon, Dagon thinks about how Toji doesn't have cursed energy and attacks with a weak shikigami. Toji easily takes care of the shikigami and attacks Dagon, causing Dagon to wonder about the power that Toji has. Dagon attacks with more shikigami but again, Toji easily dispatches them. Dagon then sends out his strongest shikigami but Toji easily destroys them and continues to attack Dagon. Toji then rubs Playful Cloud together, causing it to sharpen at its ends.
Dagon thinks about how he is about to lose to a human with no cursed energy, but notices that Megumi's power is getting weaker and that he just has to buy time. Dagon tries to escape, but Naobito blocks his path and Toji takes this chance to stab Dagon. Dagon says that it's not over yet, but Toji continues to stab Dagon until Dagon is exorcised. Dagon is then mourned by Jogo, who burns Dagon's body.
Later when Jogo is killed by Sukuna, Dagon meets with Jogo along with Hanami.
Abilities and Powers
Overall Skill Level: Dagon is a special grade cursed spirit. He has a massive amount of cursed energy that he uses to create multiple powerful attacks.
Levitation: Dagon has been shown to be able to be float in midair.
Enhanced Endurance: Dagon has a massive amount of life energy, so he can take a lot of damage and still appear as if he was in perfect condition.
- Dagon's appearance is most likely a reference to the works of H.P.Lovecraft.
- Dagon's name originates from the ancient Mesopotamian and ancient Canaanite deity. A long-standing association with a Canaanite word for "fish", perhaps going back to the Iron Age, has led to an interpretation of this deity as a "fish-god".