Boota

Boota (ブータ) is Simon's pet pig-mole.

Pig Mole Boota
For the majority of the series, Boota sticks around Simon and does very little. He mostly is comical relief but appears in almost everyone of Simon's fights. Once Boota saved Simon and Kamina by willing removing its rear end (which later grew back) as food for Kamina and Simon, revealing they can't pilot when hungry.

Evolved Boota
While in the Space-Time Labyrinth, Boota assumed a human form due to him absorbing remnants of Simon's spiral energy throughout the course of the series. While in this state, he was able to defeat the fake Anti-Spiral in one hit. Since he was now intelligent, he realized he was trapped in the labyrinth like everyone else and that this form was caused by him being in the Labyrinth. Just as with the others abandoning their fantasies, Boota returned to pig-mole form when he escaped the labyrinth and teleported aboard Tengen Toppa Gurren Lagann with his friends.

Evolved Boota is also seen during the prolouge giving orders abourd the Cathedral Terra with Simon.

Evolved Boota in the prologue.

Powers and Abilities
Increased Spiral Power:Unlike other members of Team Gurren, Boota has the ability to unleash massive amounts of Spiral Power. He was able to use it to change into a a Human form, even though it wasn't real.

Trivia

 * Boota has two spots he is usually sitting. The first is Simon's Shoulder while the second is in between Yoko's large breasts. Oddly enough, Yoko doesn't seem to mind.
 * 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.