|Home world:||None (creation)|
|First appearance:||Ultraman Mebius & The Ultra Brothers|
|Latest appearance:||Mega Monster Rush Ultra Frontier|
U-Killersaurus (Uキラーザウルス, U-Kirāzaurusu?) is a powerful choju, probably among Yapool's strongest, it later evolves into U-Killersaurus Neo (Uキラーザウルス・ネオ, U-Kirāzaurusu Neo?). It first appeared in the film, Ultraman Mebius & The Ultra Brothers.
- Subtitle: Ultimate Choju (究極超獣 Kiwami Chōju?)
- New Subtitle: Ultimate Giant Choju (究極巨大超獣 Kiwami Kyodai Dai Chōju?)
Ultraman Mebius & The Ultra Brothers
First battle against the Ultra Crusaders
In the 1980s, the ever plotting Yapool sent a new choju of his, the U-Killersaurus, to dispose of the four Ultra Brothers; Ultraman, Seven, Jack and Ace. Their battle began on the moon, with the four Ultras dodging everything U-Killersaurus threw at them.
Grappling with the beast proved futile, as it's strength was enough to hold off two Ultras at once. When the four Ultra Crusaders tried to use their beams on the choju, it flew towards Earth. The heroes tried to stop U-Killersaurus, only to be met by a barrage of his organic missiles.
Avoiding those, the Bros. prepared to launch their beams again, when Ultraman halted them; firing their beams so close to the Earth could harm the citizens. After grappling with U-Killersaurus' extendable claws, it was then that the four of them did the only thing they could do: sealing U-Killersaurus with Yapool.
After crippling U-Killersaurus by blasting off his limbs, Jack and Ace combined their Specium and Metallium Rays to send U-Killersaurus plummeting into the Earth. Then using their Final Cross Shield, the four Ultras sealed U-Killersaurus and Yapool into the bay they had landed in.
For twenty years it would remain sealed, until Aliens from; Temperor, Zarab, Guts, and Nackle would try to free the creature.
Revival and Destruction
After being revived by Alien Nackle and Alien Guts, U-Killersaurus was even more powerful than before. Yapool was revived as well, and casually killed his supposed ally, Nackle (Guts was destroyed by Mebius). As far as he was concerned, Nackle was just a pawn. U-Killersaurus then proceeded to mercilessly beat the Ultra Bros. with his new strength.
Even when Ultraman Taro and Zoffy arrived to assist the brothers, they still could not stop this juggernaut of a monster. U-Killersaurus Neo soon caught Mebius with his large pincers, and prepared his ultimate attack in order to kill him. However, the remaing Ultra Bros. combined their power with Mebius, and the result was Ultraman Mebius Infinity Mode!
U-Killersaurus Neo was helpless against the new hybrid Ultra Warrior, as he easily smashed into his body, saving Aya Jinguji who was trapped in the colossal kaiju's body and came out the other side, causing U-Killersaurus Neo to decay into dust, along with Yapool.
- U-Killersaurus is the only Choju possesed by Yapool.
- U-Killersaurus's roar was later reused for King Pandon.
- Several features of U-Killersaurus is based off of a similar choju weapon, Ace Killer.
- According to the final cutscene of Ultraman Fighting Evolution 0, The letter U in its name stands for "Ultra", which means its full name is Ultrakillersaurus (ウルトラキラーザウルス, Urtorakirāzaurusu?).
- Height: 79 m
- Weight: 82,000 t
Powers and Weapons
- Fireball: U-Killersaurus can fire massive, purple fireballs from his body. Where he fires them from is unknown.
- Saurus-Stinger: The spikes on U-Killersaurus' back can launch out and zoom around multiple enemies before exploding. Each missile is basic in power, but the sheer number of them make this a devastating attack.
- Terrible Flasher: U-Killersaurus can emit a flash of bright light from the purple orbs on his chest and shoulders. This flash can stun his opponents for a short period of time while also making them flinch. Also it can push his opponents back several yards.
- Clawed Tentacles: U-Killersaurus is equipped with numerous tentacles that can extend several hundred, possibly thousands of feet. While these tentacles can ensnare and bash opponents, each is also tipped in claws that are perfect for gripping struggling opponents.
- Boosters: U-Killersaurus has rocket boosters on his back. This allows him to fly at great speeds, even in space.
- Height: 303 m
- Weight: 939,000 t
Powers and Weapons
- Feeler Shock: U-Killersaurus Neo can fire a red beam of energy from his tail. This beam is strong enough to virtually destroy nearly any opponent in one hit.
- Killer Eye Ray: When needed, U-Killersaurus Neo can fire beams of blue energy from his eyes. The exact strength of these beams is unknown.
- Dynamite Eraser: U-Killersaurus Neo is equipped with a powerful energy cannon on its belly. This cannon can fire a beam of energy of unknown strength.
- Saurus-Full Blast: U-Killersaurus Neo's strongest attack, the death beam is fired from between its mandibles and can virtually vaporize the strongest of opponents in a single hit. If his mandibles aren't out of the way when fired, they will also be completely vaporized.
- Killer Warheads: The spikes on U-Killersaurus Neo's body can launch out and zoom around multiple enemies before exploding. Each missile is basic in power, but the sheer number of them make this a devastating attack.
- Clawed Tentacles: U-Killersaurus Neo is equipped with numerous tentacles that can extend several hundred, possibly thousands of feet. While these tentacles can ensnare and bash opponents, each is also tipped in claws that are perfect for gripping struggling opponents.
- Mandibles: U-Killersaurus Neo has a very large set of powerful, crushing mandibles on the front half of his body.
- Height: Planetary Scale
- Weight: Too massive to judge
- Origin: Unknown planet where Plasma Verokron was destroyed
Powers and Weapons
- Flight: Plasma Killersaurus can travel through space at his leisure.
- Plasma Soul Generation: It is unknown if it actually created the substance or if the pieces just fell of, but the planet sized monster caused the spread of the mineral Plasma Soul and the appearance of more Plasma Monsters.
- Endurance: Though not specifically stated but, due to the fact that it is a mutated U-Killersaurus and that it survived the crushing weight and height of a planet's innards. It is assumed Plasma Killersaurus hold great durability and/or resistance.
Mega Monster Rush: Ultra Frontier
U Killersaurus returns as the planetary scaled, Plasma Killersaurus (プラズマキラーザウルス Purazuma Kirāzaurusu?) in Mega Monster Rush Ultra Frontier VEROKRON Hunting. After defeating Plasma Verokron, the Rush Hunters returned to the Hunter Station while greeted by a cheering crowd. However they then witnessed the destruction of the planet they were fighting on, discovering that it was the home of the world sized Plasma Killersaurus. The titanic beast took of through the cosmos, spreading Plasma Soul around the cosmos and the appearance of more Plasma Monsters.
Plasma Killersaurus Hunting
Baltan Battler Barel, Guts Gunner Garm, and Magma Master Magna were secretly went to a planet filled with lava and a surface just like our Moon to find and hunt Plasma Killersaurus. Shortly after discovering it hiding, the monster woke up. The trio then ran to avoid chunks of fallen stalagmite until they stopped, discussing how Killersaurus came to this planet and how to get the monster's Plasma Souls. When the creature fully awoken, the trio endured a sandstorm, that was followed by the monster's roar and leaped high to dodge an attack. After dodging the creature's lightning bolt attack, the trio decided to attack it. Garm decided to fire his Gatling Shots at the behemoth, but it protected itself with an energy shield. Barel then launched his Lightning Boomerang at the creature, but it absorbed it into his body. Magna then summoned his Lightning Claw to attack, but the monster launched a plasma ring to knock him out of the air. He tried again, but this time, he saw a vision of a new sword before dodging another of Killersaurus's attacks. When the creature fired his lighting again, Magna deflected it, but at the price of his own weapon. Magna then retreated and was joined by the others. Killersaurus fired another lightning weapon at them, but this time, Garm countered it with his Gatling Gun. Unfortunately, he too lost his weapon afterwards. Magna then summoned his inner power and charged straight at the beast resulting in a small explosion. He may have been knocked back, but, he gained a new sword in the process. After a few moments of discussion, Magna summoned the power of the weapon, lighting it up and striking a major part of Killersaurus's Plasma Souls, and soon after, it left, but not without Magna losing his new sword.