"But an avalanche sealed Dr. Wheelo inside an impenetrable wall of ice and snow. It was as if heaven itself was jealous of Dr. Wheelo's power and genius and tried to seal his fate inside a frozen tomb."
Dr. Kochin (ドクター・コーチン, Dokutā Kōchin) is Dr. Wheelo's assistant and a self-professed expert in biotechnology. He appears as a very elderly man wearing a white lab coat, with an odd-shaped head and male-pattern baldness. Even though he appears old and harmless, Dr. Kochin is actually well-equipped for fighting: his hand can transform into a machine gun, while his cane, which bears a stylized headpiece of Shenron, can hurl energy blasts.
The World's Strongest
Main article: Dragon Ball Z: The World's Strongest
Dr. Kochin is the one who saved Dr. Wheelo from death and transformed him into a cyborg. Kochin, along with Wheelo, also created the three Bio-Warriors: Kishime, Misokatsun and Ebifurya. He later gathers the Dragon Balls and uses his wish to free Dr. Wheelo from his icy prison in the Tsumisumbri Mountains after fifty years.
Dr. Kochin captures and brainwashes Piccolo while the latter was training on the Tsumisumbri Mountains thanks to his Bio-Warriors, and he later kidnaps Bulma and Master Roshi at Kame House with the Bio-Men's help. Dr. Kochin spends the remainder of his time inside Wheelo's fortress, commanding the actions of the bio-fighters from the control room. The first evidence that Kochin is more than he seems comes when he attempts to kill Krillin. He lifts his arm and the skin on his hand rips away, revealing a mechanical hand underneath, which then transforms into a rotating machine gun. His gunfire damages some of the equipment powering the force field which holds Bulma prisoner, freeing her, but also leaving her open to attack. As Kochin takes aim, Master Roshi attacks him and knocks his gun-arm off by unknown means.Literally disarmed, Kochin stands back and watches in shock as Dr. Wheelo begins wrenching his giant mechanical body free from the laboratory wall. As he steps out onto the laboratory platform, Wheelo's giant foot accidentally knocks Kochin off the edge and he falls down from the main shaft. As he falls, his body gets too close to the glowing dais which supports the laboratory above, and bolts of electricity arc out and strike Kochin's body, causing his clothing and skin to burn away, revealing a robot underneath. He mutters Dr. Wheelo's name, before exploding in midair.
- Flight – The ability to fly using ki. Used in Dragon Ball Heroes.
- Ki Blast – The most basic form of energy wave. Used in Dragon Ball Heroes.
- Madness Wand – An energy-generating device. The top of Dr. Kochin's cane can tilt forwards, revealing a button. When this button is pressed, a gigantic blast of energy shoots out of the cane. Kochin uses this attack against Gohan in the film, and has it in the arcade game Dragon Ball Heroes.
- Vulcan Cannon – Dr. Kochin's left hand can transform into a rotating machine gun. Kochin revealed this machine gun and used it in an attempt to kill Krillin. Super 17's Hell's Storm attack is similar to this attack.
Dr. Kochin made his video game debut in the Japanese only arcade game Dragon Ball Heroes as part of the sixth mission of Jaaku Mission series (JM6).
- Japanese: Kōji Yada (originally), Tetsuo Goto (Dragon Ball Heroes)
- Ocean Group dub: Paul Dobson
- FUNimation dub: Troy Baker
- AB Groupe dub: Paul Bandey
- Brazilian Portuguese dub: Walter Breda
- Much of Kochin's past is unexplained. All that is known is he was Dr. Wheelo's assistant, and that he is an android. It is unknown if he was originally a human and simply put himself in an android body to prolong his life (a similar backstory to the later villain, Dr. Gero), or if he was a creation of Wheelo (like Dr. Gero's Android 19).
- Also unexplained are the events surrounding his death. Precisely why the dais glowed like they did and shot out bolts of electricity when the falling Kochin drifted too close is never explained. Most likely, this was caused by Wheelo, who was powering up. Another possibility is the energy flowing through dais was attracted to Kochin's metal body underneath his exo-skin.
- The fact the handle of his cane is designed to resemble Shenron hints at a fifty-year obsession with the Dragon Balls.
- In the Jaaku Mission Trailer 6, Dr. Kochin can be seen standing alongside other Dragon Ball series other mad doctors, Dr. Gero, Dr. Myuu, & Dr. Raichi.
- Dr. Kochin's name comes from the Nagoya Cochin, a regional variant of the Cochin chicken. This is part of a theme with the rest of the villains from The World's Strongest being named after food from the city of Nagoya, Japan.