Boota (ブータ, Būta?) is Simon's pet Pigmole.
For the majority of the series, Boota sticks around Simon and does very little. His main role is comic relief, but he appears in almost every one of Simon's fights. Once, Boota saved Simon and Kamina by willingly removing his rear end (which later grew back) as food for Kamina and Simon, revealing they can't pilot when hungry. He also tries to comfort Simon in moments of distress, but even his best efforts couldn't snap Simon out of his depression over Kamina's death.
Later on, Boota helps Yoko overcome her memories of Kamina when she pilots Gurren in Rossiu's place. He accompanies the young sniper when she is injured within the Dai-Gunten, but finds himself helpless when the Shuzack enters the scene. Nonetheless, Yoko claimed that Boota was around to protect her, earning a big lick from the Pigmole.
When the Super Galaxy Dai-Gurren is trapped in the Sea of Despair, Boota aids Simon and Viral by generating Spiral power of his own to bolster the ship's defenses. After Antispiral was defeated, he becomes Simon's lone companion during his journey across the earth.
While in the Multiverse Labyrinth, Boota assumed a human form due to his assimilation of Lordgenome's Spiral Energy into his own already large portions of Spiral Power. He is the unknown source that Antispiral detected which prevented their immediate destruction. While in this state, he was able to destroy Antispiral in one hit, but shortly after, the latter reformed his body. Since he now had intelligence, he became trapped in the Labyrinth like everyone else. Boota returned to Pigmole form when he escaped the Labyrinth and teleported aboard Tengen Toppa Gurren Lagann with his friends.
Spiral Power: As a Spiral Being, Boota is capable of utilizing the power of evolution, which becomes significantly magnified when the user's willpower increases. His first instance of awakening Spiral Power was in episode 25, where he temporarily took an exhausted Simon's place in powering Super Galaxy Dai-Gurren. Later after Simon recovers, they both pour their Energy into the mech for the rest of the time. The novelization reveals that Boota's Spiral Power made Gurren Lagann more powerful than it had ever been before, when Simon was powering it; meaning Boota had become the most powerful Spiral Being after his awakening of Spiral Power, shortly before the team escaped the Multiverse Labyrinth. In episode 27, Boota, like all other members of Team Dai-Gurren at the time, has unlocked and has access to infinite amounts of Spiral Power (via being given the same power as Simon), and is capable of using it in any possible way. Similar to Lordgenome, Boota is capable of utilizing his Spiral Power to increase his body's physical stats. Additionally, his Spiral Power becomes visible when integrated in such a manner. He uses this to initiate a hand-to-hand fight with Antispiral.
- Spiral Power Forcefield: During the time where everyone but Lordgenome and Boota were trapped in the Multiverse Labyrinth, Antispiral had come aboard the Super Galaxy Gurren Lagann to eliminate the unknown source of Spiral Power, to which he assumed was Lordgenome. As he fired an energy shot towards him, Boota had intercepted the attack by projecting Spiral Energy omnidirectionally, creating some sort of forcefield.
- Energy Absorption: Shortly after Boota discharged his Spiral Power, Lordgenome had released his own Spiral Power, to which Boota took in, and made it his own power.
- Transformation: When Boota assimilated Lordgenome's Spiral Energy, he had gained the necessary levels of Spiral Power to unfathomably enhance his power to evolve, so much so that he instantly assumed a more humanoid version of a Pigmole.
Regeneration: In episode 4, Boota rips off his butt to satisfy Simon and Kamina's hunger, mid-fight. Immediately after the fight, he is shown having this piece of his body back. After the creation of the Tengen Toppa Gurren Lagann, all members of Dai-Gurren were given the ability to reform their bodies as long as their consciousness exists; demonstrated by Lordgenome.
Extrasensory Perception: Boota is capable of seeing and even touching Antispiral; an invisible being who's body is of the entire Anti-Spiral Tribe's consciousness.
- In Episode 2, it's revealed that Boota apparently wears glasses (which greatly resemble his black eyes).
- Boota, like Leeron, also does not appear to age, being seen with Simon during both the 7 and 20 year time advancements with no notable change in appearance. This is strange considering that much larger, older Pigmoles are seen in the first episode, and when Rossiu is loading the Arc-Gurren, implying that they grow with age. However, Boota doesn't grow. It is attributed to the fact that Boota turned his individual growth energy into species evolution energy. This allowed him to evolve, but prevents him from growing.
- Boota (in his evolved form) is possibly Simon's right hand man in the prologue or the series as the two characters share a striking resemblance.