|Height:||20 cm ~ 38 m|
|Weight:||20 kg ~ 5,000 tons|
|Place of Origin:||An unknown comet|
|Transformation Item:||Ai Kumasiro|
|First Appearance:||Bio Planet WoO episode 1 "He Fell From Outer Space!" (あいつが宇宙から落ちてきた！ Aitsu ga Uchū kara Ochite Kita!?)|
|Last Appearance:||Bio Planet WoO episode 13 "Bonds to the Future"|
WoO (ＷoO（うー）, Ū?) is the only survivor of his species and wandered in space on a comet until he crashed on Earth. There, he met Ai a junior high school 2nd year student who’s school is then attacked by a giant monster, which resulted in her being the lone survivor of the attack after their encounter. WoO develops a strong bond with her saying that he will protect her at any cost. He uses his antennae to connect to electronic devices (mainly a cell phone) to communicate with her. Both are chased by a mysterious organization called SWORD who sees WoO as a threat to humanity. At the same time giant monsters have begun to invade the Earth in search of WoO who must now fight both SWORD and the monsters for his survival.
Subtitle: Biological Comet (生物彗星, Seibutsu Suisei?)
Bio Planet WoO
The shape WoO used to travel in space. WoO reverts to this form due to exhaustion fighting as a giant. It takes water to revive him into his normal form. It is also called Fossil form by some.
Normal Form WoO's usual form.
- Length: 20cm
- Weight: 20kg
- Flight Speed: Unknown
- Transform: When needed, WoO can transform into his inflated form or merge his energy with another being to become Aikichi WoO. He can also transform his body to blend in with his surroundings, becoming the shape of something like a backpack.
- Kaiju: When angered or afraid, WoO’s eyes will glow red and he will accidentally summon an alien kaiju that will fall from the sky in a meteor a short distance from his location. These kaiju are completely uncontrollable and WoO himself usually has to fight them in his inflated or Aikichi forms.
- ESP: Signified by the tip of its crest glowing, WoO can use psychic powers to operate electrical equipment from a distance or repair things. Using it too much will revert it to its Egg Form.
An expanded version of normal form; WoO grows bigger than Ai, but still fights monsters in its normal form.
Due to WoO's shapeshifting abilities, he takes this form when traveling with Ai to disguise himself from the public.
Aikichi Version (アイ吉バージョン, Aikichi Bājon?)
- Height: 38 m
- Weight: 5,000 tons
- Rebound Crash: By forming a cannon ball with his body, Aikichi WoO can launch himself out an opponent. On contact, an explosion will burst from impact and send a surge of energy through the opponent, destroying all but the strongest enemies in a larger explosion.Used in episode 3.
- Tornado Kick: When needed, Aikichi WoO can spin his body around at such high speeds that he will form a tornado, capable of lifting up trucks and cars off the ground. As he spins around, he can kick the objects out, launching them at an opponent. Once this attack is finished, WoO will be extremely dizzy for a short period. Used in episode 4
- Spinning Attack (Aikichi version): Gil eye version of the high-speed rotation WoO was also used. Used in the third story, fourth story.
- Ice Chute: When kicking a small vile of water, Aikichi WoO can increase the amount of water that shoots out. A small glass can turn into several large blasts of water that fly forward. Used in episodes 3 and 4.
- Aikichi fist: Punch you shoot to let Minagira energy to the whole body. Used in Episode 10.
- Spinning Attack: Shoot with the eye, enhanced version of the spinning attack. Defeated the Nagakura that became a Gerunoido using in Episode 13.
After a battle Aikichi WoO will turn into a small fossil-like object that can only be revived by water.
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||Gridman | Servo | WoO | Mirrorman Reflex | Gridman Sigma | Don Shine|
||God Zenon | Dyna Dragon | Mountain Gulliver No. 5 | Reimon | Mirror Knight | Glen Fire | Jean-Bot | Jean-Nine | War God|