Minotaur

The Minotaur (Μινώταυρος in Ancient Greek, meaning Minos Bull (Mino - King Minos and tauros - bull/cow)) was a creature with the head of a bull on the body of a man. He can't speak and is rather dull headed. However, he does have great strength and is easily angered. Like all monsters, the Minotaur can't be fully killed, and it will just keep coming back. The Minotaur was one of the first monsters encountered by Percy in The Lightning Thief. The minotaur is one of the most famous monsters in Greek mythology. Percy defeated it once again in the Last Olympian.

History
The Minotaur was born of a human, Pasiphaë, and a white bull. Poseidon sent the white bull to King Minos for him to sacrifice in his honor, but King Minos did not sacrifice the bull because he saw that the bull had the most beautiful fur that he has ever seen and let the bull live. However, Poseidon was spying nearby and saw that Minos had left his white bull alive. Thereafter, mad with rage and anger that Minos had not sacrificed the bull, curses Minos and cursed that Pasiphae will fall in love with the bull. Poseidon then leaves for Olympus. She had Daedalus make a fake cow for her to hide inside and lure it.

The result of their union was the Minotaur.

Pasiphaë nursed him in his infancy, but he grew rapidly and became incredibly ferocious. Minos, after getting advice from the Oracle at Delphi, had Daedalus and his son Icarus construct a gigantic maze, the Cretan Labyrinth, to hold the Minotaur. Its location was near Minos' palace in Knossos.

The Minotaur dwelts at the center of the Labyrinth and every three years, seven youths and seven maidens in Athens were taken from their families as sacrifices to him. Theseus, the son of Aegeas, volunteered to slay the Minotaur and was taken to the Labyrinth as a feast for the monster. The Minotaur was eventually killed by Theseus with the help of Ariadne.

The Lightning Thief
In the first book, The Lightning Thief, Percy Jackson is running to Camp Half-Blood when Minotaur attacks. He is described as having fur from about the belly-button on up and naked except for a pair of bright white Fruit of the Loom briefs. Percy manages to jump onto the Minotaur's back, pulled off one of the its horns and killed it by stabbing it in the side. Percy kept the horn as a war spill, after Grover returned it from the scene of the battle. It is also noted by Annabeth, that many campers where hoping to achieve such a task for many years.

The Minotaur almost kills Percy's mother, in fact, Percy is convinced she is dead, but she is actually held hostage by Hades in the Underworld and is later released after Hades' Helm is returned.

The Last Olympian
In The Last Olympian, the Minotaur had reformed and was made a general for one of Kronos' Titan armies. He attacked Percy Jackson again when leading the Titan Army across the Williamsburg Bridge in Manhattan. Even though his armor made him more difficult to kill, Percy was more experienced and stronger. Percy also had the advantage of bathing in the Styx, granting him invulnerability and increased stamina and strength.

Weapons
In The Last Olympian, the Minotaur wielded a huge axe with blades in the shape of the Greek letter, Omega. Percy guessed that, that was because it would be the last thing his (the Minotaur) enemies saw (The letter Omega is the last letter in the Greek alphabet).