Minotaurus

Minotaurus is one of the four Demon Guards in Impel Down and the first one to appear. He is an "awakened" Zoan Devil Fruit user that ate a fruit who turned him into a cow.

Personality
A cold, heartless Demon Guard! A monster who treats humans like so much trash!

Despite his appearance, Minotaurus is a cold-blooded beast. He would brutally bludgeon rioting prisoners and opponents alike with his spiked club. He would often do so aimed at their skulls. Because of his savagery, the various prisoners of Impel Down fear him, like the Demon Guards.

He acknowledges Sadi-chan's superiority in battle, even fearing her when she got angry over his failure.

Abilities and Powers
As one of the Demon Guards of Impel Down under Sadi-chan, Minotaurus is in charge of torturing and maintaining the various prisoners.

While he doesn't look like a powerful opponent, Minotaurus is in reality a fearsome beast. He has immense physical strength and speed, along with excellent resilience. Wielding his spiked club as a weapon in conjunction with these attributes, he is a lethal force to be reckoned with.

Devil Fruit
He has eaten an as-of-yet unnamed Zoan type Devil Fruit that allows him to become a cow. Because he is an "Awakened Zoan", he is able to recover rapidly even after suffering high amounts of damage.

Impel Down Arc
It is first seen beating two prisoners up for fighting and locking them up in a cell for death row, then again beating Jinbe in Level 6. Although only its shadow is shown during those times, it is clear that it is a Minotaur that shows no fear. (though at the time, Jinbe was chained down and Jinbe also states that it did not hurt him).

Later as Luffy reaches the Starvation Hell of Impel Down, it gets the order to battle him as well as Mr. 2 Bon Kurei, who was supporting Luffy. However, as soon as it sent Mr. 2 flying with a single hit, Luffy recognized its true powers and immediately activated Gear Second and used his Jet Bazooka to send Minotaurus flying to save Mr. 2.

Although Luffy used one of his powerful techniques to defeat Minotaurus, it appeared later, hunting Buggy and Mr. 3 (it landed on top of them when Luffy sent it flying). At one point they come to meet Luffy and Mr. 2. Buggy used his secret weapon, the Muggy Ball, to take Minotaurus down, but even after a huge explosion it was still conscious. Even when Mr. 2 used a strong kick to finish it off, it stood still but was in great pain. Only as Luffy and Mr. 3 combined their abilities to use the Gomu Gomu no Tonkachi Rifle, they could fully defeat Minotaurus. He was last seen falling from level 3.

Later, he fully recovered (albeit bandaged) and joined the battle against the rioting prisoners. Despite all of this, he was defeated (as well as receiving his comeuppance for beating Jinbe earlier) with the rest of the demon guards by Monkey D. Luffy, Crocodile and Jinbe in level 1.

Major Battles

 * Minotaurus vs. Monkey D. Luffy, Mr. 2 Bon Kurei, Mr. 3 and Buggy (Level 3)
 * Minotaurus vs. Impel Down Prisoners and Residents of New Kama Land
 * Minotaurus, Minokoala, Minorhinoceros and Minozebra vs. Monkey D. Luffy, Crocodile and Jinbe (level 1)

Filler Battles

 * Minotaurus vs. Monkey D. Luffy (Level 4)

Anime and Manga Differences
In the manga, the spikes on his club were sharp like nails, but in the anime the spikes are edited into flat, round spikes, due to the spikes being related to the theme of torture. Also, in the anime, Minotaurus has an extra battle with Luffy alone.

Trivia

 * Zoro's design for Mugiwara Theatre - Monster Time is similar to Minotaurus in many ways. Both carry identical clubs, are minotaurs that resemble cows and both have patches in similar places to each other.
 * Minotaurus' name is a combination of Mino and Taurus, Mino, an ancient Greek city and the origin of the Minotaur legend, and Taurus the Latin name for bull. This naming combination is shared with his fellow Demon Guards.