- "I AM A COW! C-O-W!"
- —Taurus in a fit of rage.
Taurus, known as Ox (オックス Okkusu?) in Japan, is a character of the MegaMan Star Force series based on the constellation Taurus. He is an extremely strong, armored bull with the bashfulness of a bull as well. He emits fire to propel himself forward or burn his enemies. When he fuses with Bud Bison, he becomes Taurus Fire (known as Ox Fire (オックス・ファイア Okkusu Faia?) in the original version).
In Mega Man Star Force, Bud Bison attempted to threaten Geo to go to school for Luna. Omega-Xis' brash personality causes Geo to punch Bud, leaving him embarrassed and his companions questioning their association with him, with Luna threatening to cut off their BrotherBand, which Bud feels would make him a nobody.
Taurus acts on his anguish, offering him the power to get revenge on Geo and earn Luna's respect. Under Taurus' control, Bud begins randomly destroying red objects in the real world. When he, Luna, and Zack go on patrol, they encounter Geo, whereupon Bud transforms and escapes into the cyber network of a truck that Luna and Zack are riding in, driving it recklessly through the city and attempting to run Geo over. Afterwards, Bud has little recollection of the incident, only that he did some terrible things.
Taurus is later resurrected by Cepheus, and goes with the other FM-ians to confront Omega-Xis and take the Andromeda Key. After they defeat Mega and Harp Note, Geo arrives to help Mega, prompting the FM king to withdraw the FM-ians from Earth. When Megaman arrives at his father's space station, Taurus is at the second door. After being defeated he nearly says that Mega was a true AM-ian before disappearing in a flash of light.
Taurus Fire re-appears in MegaMan Star Force 2 as a mini boss. During an eating competition, Bud is put under so much pressure that it makes his memory of Taurus from MegaMan Star Force reappear and wave change with him. After defeating him in battle, the player instantly gains his battle card.
He also re-appears in MegaMan Star Force 3, where he is awakened from a dormant state inside of Bud by a Noise Card from Jack. After Taurus Fire is defeated and the Noise Card is removed, Taurus apologizes to Bud for all of the trouble he has caused, and vows to make up for it as Bud's Wizard. He and Bud are registered under the Satella Police's Project Transcode as No. 005. Taurus also appears in this game as a Noise form that MegaMan can change into. He later helps MegaMan when he goes to fight Diamond Ice.
In the anime, Bud grows jealous over Luna spending so much time with Geo upon his return to school, when Taurus arrives upon sensing Bud. After being thrown into a hallway by Omega-Xis in the first confrontation, Taurus enters Bud's body and uses him as Taurus Fire until he is defeated and Taurus is forced out of him. Later, Taurus takes on the form of W Bud while gathering minus energy to recreate the Andromeda Key. He is the first FM-ian to be ultimately deleted by Gemini Spark in order to refill the real Andromeda Key with minus energy.
In the final episode of tribe, he is seen behind Bud along with the other FM-ians who have been revived and are watching Sonia's show.
In the manga, Bud encounters a gang of street thugs who bully him and an innocent puppy. Taurus subsequently targets Bud who desires the power to overcome the bullies. However, after being defeated by Mega Man, Taurus becomes an ally of Omega-Xis's and reveals that the "Star Force" will help Geo find his father.
Taurus is the name of one of the constellations of the zodiac. It is between Aries, to the west, and Gemini, to the east; to the north lie Perseus and Auriga, to the southeast Orion, to the south Eridanus, and to the southwest Cetus.
Taurus is also the second astrological sign in the zodiac, originating from the constellation of Taurus. In astrology, Taurus is considered a "feminine," negative sign. Taurus is ruled by the planet Venus (which also rules Libra). Anyone who is born in May is considered a Taurus.
- Taurus refers to himself as a cow, despite the fact that he is male. This might to prevent confusion among children 3 years old and under, who usually taught the single 'cow' vocabulary in Kindergarten to refer both bull/cow, regardless of the gender.
- There are un-uploaded unused Sprites of FM-Ians using their attacks while not wave changed outside Wave battle, however, this does not apply to Gemini, he is clearly seen using Gemini Thunder and NS Tackle.