Tretista Kelverian

Tretista Kelverian (トレテスタ・ケルベリアン) is one of the bosses in Mega Man Zero 3. Tretista is based on Cerberus, the three headed hellhound. He is one of the Eight Gentle Judges, and has three independent thought circuits that he uses to reach a fair judgement. These circuits act as the voices of compassion, aggression, and reason. When Dr. Weil brainwashed him to be one of Weil's Numbers, he could not think properly. Instead, his aggressive traits were amplified, furthering his beast-like nature, and he became violent and arrogant. When Zero went to investigate a giant elevator created by Neo Arcadia, he finds Kelverian protecting it, fighting him. Zero then discovers the elevator is used to transport mass amounts of E-Crystals to be used as energy. As with the other Judges, Kelverian reappears in the final stage, but is defeated again by Zero.

Strategy
Tretista attacks by separating the dogs attached to his shoulders, which then jump around the room, throwing a box and then dashing to destroy it, spitting vaporous energy balls across the floor, and bending a metal bar into a V shape and then tossing it like a boomerang. At A or S rank he will use his EX attack, where a large laser occasionally comes from his claw when he dashes to the box.

Defeating him gives Zero the Absorber Body chip and, if at A or S rank, the Gale Attack ability.

Attacks

 * Hellhounds - Tretista will detach his arms summoning two hound that will try and jump at Zero.
 * Box Rush - Tretista will grab a giant box and tries to throw it at Zero, then dashes at it to destroy it.
 * Purple Orb - Tretista and his dog heads on his shoulders spit purple energy orbs that roll on the floor before disappearing.
 * Pole Throw - Tretista will grab a pole, bend it into the shape of a boomerang, and try to throw it at Zero. If shot with the Z-Buster while it is in mid-air, the pole will go back and hit Tretista instead.
 * EX Skill: Laser Claw - Tretista Kelverian drops a large crate on the ground similar to his other box attack. If the player is fighting Tretista at A or S rank, he will summon a giant purple laser sword at the crate.

Data
Nickname: Rabid Dog Protection (咬哭の守護 Koukoku no Shugo)

EX Skill: Laser Claw (レーザークロウ)

Mission: Search Facility

Zero's EX Skill: Gale Attack (Reppuugeki)

Stage enemies
Enemies in Tretista Kelverian's stage.
 * Sub-boss: Spearook
 * Batring
 * Cattatank
 * Eye Cannon
 * Flopper
 * Pantheon Guardian
 * Pantheon Fist
 * Shotcounter
 * Shotloid

Trivia

 * Tretesta (Tretista) comes from Italian tre (three) and testa (head); also, tritesta is Italian for three-headed, while Keruberian (Kelverian) is a play of Kerberos (ケルベロス Keruberosu; also known as Cerberus in English). Therefore, his name means "Three-Headed Kerberos".
 * In the English-localized Mega Man Zero 3 instruction manual, Tretista is better translitterated as "Tretesta Kerberion".
 * Tretista breaks the tradition of having two life bars as one of the eight main bosses in the Mega Man Zero series, having a third bar and surpassing the other judges' health.
 * Tretista and Childre Inarabitta are the only members of the Weil's Numbers that first appear to Zero already morphed in their Punishment forms. He only assumed his humanoid form briefly during the final stage, morphing afterwards.
 * Coincidentally, Tretista's appearance is similar to that of Omega's second form, in that they both have heads attached to their shoulders instead of closer to the middle head.
 * The boss Bifrost the Crocoroid from Mega Man ZX Advent has an appearance that is quite similar to that of Tretista. Both have similar standing animations, and both have an attack that sends a rolling weapon across the floor.
 * His three heads having a different thought system for judgement could be a reference to the three judges of Hades Rhadamanthys, Eacus, and Minos.
 * If Tretista manages to drop one his crates on Zero at a corner, it is an instant kill regardless of Zero's vitality.