- Ultraman Geed: Belial Fusion Monster (ベリアル融合獣 Beriaru Yūgō-jū)
- Ultraman Taiga: Cultivated Synthetic Monster (培養合成獣 Baiyō Gōsei-jū)
Skull Gomora first appeared as summoned by Kei Fukuide to kill Laiha Toba's parents, to extract her Little Star. Afterwards the Kaiju vanished, as Kei had finished his objective.
Six years later, the Kaiju reappeared as he rampaged in Hoshiyama where Riku Asakura and Pega were living in. When the monster eyed Riku with his boss, he destroyed the building the two lived in with one mighty stomp. Afterwards, he kept rampaging on throughout the whole day, forcing the entire population to evacuate and leaving a path of destruction behind him, as he made his way west towards Kadono.
As night fell, the monster appeared at his destination and then disappeared shortly afterwards. It was soon revealed that Kei Fukuide used a Riser and the Kaiju Capsules of Gomora and Red King to transform into Skull Gomora to wreak havoc in Hoshiyama again once his capsules thawed out. As he set his sights on a fleeing crowd of people, a girl began to glow gold within his sight, but he was later confronted by Ultraman Geed.
During their fight, despite the fact that Geed held his ground, Skull Gomora gained the upper hand in their conflict and the status remained the same when they took their fight to a large artificial lake within the city. The fight went on for quite a while, then Geed's Color Timer began to flash after Skull Gomora unleashed his Skull Oscillatory Wave on him at point blank range, knocking him down for quite a while.
Skull Gomora then turned his attention towards the citizens of the city again, but before he could attack them, Geed recovered and blocked the monster's path once more. Skull Gomora decided to end the fight with his Skull Oscillatory Wave, but Geed stood his ground and gathered enough energy to fire the Wrecking Burst at the monster, destroying him.
That wasn't the last of Skull Gomora, however. After Kei killed Dada for his failure in capturing his target, Kei used his Kaiju Capsules and Riser to transform into Skull Gomora once again at night and rampaged throughout the city again the next day and once again, Riku transformed into Geed to stop him, only this time, Riku did so after overcoming his anxieties about being the son of Belial thanks to Pega's encouragement.
Due to some experience from the last time they fought, Geed had a lot more experience under his belt and actually gained the upper hand on the fusion monster by dodging his attacks precisely and attacked with poise. Soon afterwards, Skull Gomora channeled some energy into his foot and stomped it onto the ground, summoning fire balls that rushed toward the Ultra, only for him to summon his Geed Barrier to protect himself from the attack.
However, this left the Ultra wide open for Skull Gomora to head-butt him so hard, he was sent flying and crushed a building upon landing and once again, the fused Kaiju resumed his objective of finding the girl without finishing off the Ultra. And once again, Geed got back up after he realized that the Kaiju was after Eri. and interfered with the kaiju's rampage once more. The Ultra stood his ground against Skull Gomora and tried to push him away as he kept on going and only stopped when the Kaiju bit him on the shoulder.
Once he had him on a hold, Skull Gomora attempted to finish off Geed with a fire stream attack, but the Ultra kept hanging in there and charged up his Wrecking Burst. The battle finally ended when Geed used his strength to push his face up when the Kaiju finally launched his attack and then Geed laid down on the ground and fired his Wrecking Burst at Skull Gomora, destroying him once again. As Kei kept Skull Gomora's Kaiju Capsules, which were the first of seven that Kei needed, Riku obtained the Ultra Capsule for Ultraman Leo from Eri via her Little Star, resulting in her losing that said object, which gave her pyrokinesis and target for monsters and aliens.
Skull Gomora appeared much later in the Mitsuse Foothills where Ultraman Geed was fighting Tyrant, as his presence was detected by RE.M. He would later engage said Ultra as he attacked him from above after he let Ultraman Zero take care of the other chimera kaiju. After a little while, Geed transformed into his Solid Burning form and held the advantage over the chimera Kaiju with his power. Skull Gomora then noticed the Little Star hiding within Mayu and went after it, only for Geed to summon his Geed Claw and charged head on at Skull Gomora, and sent him crashing. Skull Gomora then fired his Flame Radiation at Geed, only for him to deflect it with the Geed Claw and finish him off with the Corkscrew Jamming, which he survived for a little while until he eventually blew up. Afterwards, Riku received Zero's Ultra Capsule from Mayu, which held promise to him to the future.
- Suit actor: Kenji Kajikawa
- Paralleling Orb and Geed's similarity in their usage of past Ultras' powers, the similarities of Skull Gomora's components are as follows:
- Both are subterranean, dinosaur-like monsters that made their debut on Ultraman.
- They both resided on islands (Tatara Island and Johnson Island respectively).
- Both were proposed to be revived by Geronimon, but were ultimately scrapped and changed to Dorako and Telesdon.
- They made their returning appearance in Ultraman 80 as later generations, in Ultraman Max as their gigantic selves, Ultraman Mebius as Yapool's associates, Ultra Galaxy Mega Monster Battle: Never Ending Odyssey as the resistance of Reiblood-possessed Armored Darkness and finally in Ultraman X as victims of Greeza.
- They are the only monsters whose EX forms in Ultraman Fighting Evolution Rebirth were given suits and are the only EX monsters to reprise their roles in the Heisei Era Ultraman Series. Interestingly in the arcade game ULTRA MONSTERS, they also possessed a tag-team attack, Explosive Heat Oscillatory Melt Break.
- They are used by Reionics protagonists; Rei, Io Mikura, Kanegon, and Ai Asama.
- Their variations' powers are frequently channeled by collectible-themed Ultras; Ultraman Victory utilizes EX Red King Knuckle and Ultraman X utilizes Gomora Armor.
- On the Kaiju Card of Skull Gomora for Ultraman Fusion Fight!, his element depicted as Wind which is a rather strange choice as he neither flew, levitated off from the ground, or use wind-based attacks with a similar case happened with Sadis.
- Skull Gomora's ability to breath flames could be considered a case of adaptation liberties, as neither Red King or Gomora, have been able to have this power the majority of their appearances.
- However, Super Gomora from The 6 Ultra Brothers vs. The Monster Army film was able to fire a type of flame breath, although this is most likely a coincidence.
- During Skull Gomora's second fight, Skull Gomora bites Geed on his right-hand side shoulder. This could be a reference to 80, where Red King III performed the exact same stunt to 80.
- Koichi Sakamoto who directed Geed's first four episodes, the water battle battle in Skull Gomora's first fight was a tribute to the fight with Alien Magma and the Giras Brothers in Leo's first episode.
Skull Gomora was created by Alien Chibull Mabuze, who wanted to create the ultimate creature. He had somehow acquired cell samples of Gomora, Red King and Ultraman Belial, which he used to cultivate Skull Gomora in his lab. Mabuze reveals and unleashes Skull Gomora after Hiroyuki and Kanta are caught by his Chiburoids. Luckily, Homare Soya comes to rescue them, allowing Hiroyuki to transform into Ultraman Taiga. As a result of him using the Kaiju Rings, Taiga's fighting style becomes increasingly aggressive as he demands more power. After transforming into Photon Earth, he chops off Skull Gomora's horn and engages in what seemingly appears as a one-sided slaughter. Taiga also uses the Gigadelos Ring to clone himself and blast the monster, before throwing into a building it and finishing it off with the Aurum Strium. After the battle was over, Taiga came to his senses and was shocked by his own actions.
- Unlike previous appearances of Skull Gomora, which were technically restricted to merely being Fusion Rise forms, this Skull Gomora is fully biological and its own entity as a result of Mabuze's experiments in genetics.
- Episode writer Takao Nakano recalculated past appearances and stories in order to make Skull Gomora return in this season. Another writer Aya Satsuki proposes the idea of cultivating Belial DNA in said episode as it would provide an excuse to bring Imit-Ultraman Belial into episode 23.
A Celebro-possessed Shinya Kaburagi transformed into Skull Gomora, as well as Thunder Killer and Pedanium Zetton, after managing to forge the Belial Medal by using Riku's genetic data. Ultraman Z and Ultraman Geed faced the Belial Fusion Monsters, but were having difficulties due to Celebro's form changing. Suddenly, Ultraman Zero appeared, and the three of them managed to turn the tide on Celebro and defeated him with a combination of the Zestium Beam, Wide Zero Shot and Wrecking Phoenix.
- Since Celebro lacks a giant combat form of his own, scanning the toy release of Kaburagi's Ultra Access Card into the Ultraman Fusion Fight: Z Heat resulted with Skull Gomora appearing in his place. Because Skull Gomora is a separate being on its own, it is also impossible to perform Ultra Fusion gimmick on said arcade game.
"Gomora! Red King! This is the end mark."
- ―Kei's pre-transformation announcement
"Fusion Rise: Gomora! Red King!"
- ―Activation announcement
"Ultraman Belial: Skull Gomora!"
- ―Transformation announcement
- Height: 57 m
- Weight: 59,000 t
- Origin: Mt. Mitsuse (First sighting)
- Arm Strength: 200,000 t
- Weakness: Skull Gomora can only remain active until the component Kaiju Capsules overheat as a result of either prolonged use or being defeated in battle. They need to cool down before they can be used again.
- Powers and Weapons
- Rock Throwing (岩石投げ Ganseki Nage): Based on Red King from the ULTRA MONSTERS arcade game, Skull Gomora can summon a boulder from the ground to throw towards the enemy. This is part of the normal techniques of Fusion Fight!.
- Skull Oscillatory Wave (スカル振動波 Sukaru Shindō-ha): A burst of powerful energy released from Skull Gomora's horns.
- Skull Super Oscillatory Wave (スカル超振動波 Sukaru Chō Shindō-ha): A beam version of the Skull Oscillatory Wave, and it is more powerful.
- Shocking Hell Ball (ショッキングヘルボール Shokkingu Heru Bōru): Skull Gomora charges up energy and stomps the ground, summoning multiple fireballs which then fly at its opponent.
- Inferno Magma (インフェルノ・マグマ Inferuno Maguma): A breath of flames from the mouth.
- Brute Strength: As both of its components are naturally strong Kaiju, it inherits their brute strength and can easily match Geed Primitive.
- Tail Whip: In a fashion to Gomora's Mega-ton Tail, it can batter its enemies.
- Ultraman Taiga
- Body Lightning: Skull Gomora can release electricity from the red horns and spikes on its body.