- Classification: Zangyaku Choujin
- Homeland: Siberia, USSR
- Height: 279 cm
- Weight: 400 kg
- Age: Unknown, but has been alive since at least the last Ice age
- Choujin Kyoudo: 78,000,000 Power
- Trademark Techniques: Powerful Nose Breaker, Nose Fencing, Ice Rock Gyro
- First Appearance: Manga Chapter 274, Anime 2 Episode 2
Mammothman is a mastodon choujin who appeared as a member of Kinnikuman Super Phoenix's team during the final story arc of the manga. His trademark was extending tusks that seemed to have a mind of their own, and would seek out and impale any exposed blood nearby.
In Kinnikuman Nisei, it has been hinted that Mammothman may be the true identity of Warsman's tag partner Michael, based on Neptuneman tasting and recognizing the ice that fell out of Michael's costume. In the most recent chapters, this has been confirmed.
- Using his trunk he lifts them up in the air, then places his knee out and performs a devastating backbreaker on them.
- Nose Fencing (ノーズフェンシング?)
- His trunk elongates and becomes pointed at the end, he uses this to impale his opponents.
- Ghost Canvas (ゴーストキャンバス?)
- He slams his opponent's head into the canvas so it is stuck, then twists the body until the head snaps off.
- Ice Rock Gyro (アイス・ロック・ジャイロ?)
- He lifts up his opponent with his trunks and throw him/her into the air. While in mid-air, the opponent starts to get whipped by Mammothman's trunk. The opponent starts to freeze into a solid block of ice every time he/she gets hit.
Mammothman first appeared at Kinnikuman's coronation, where he prevented Kinnikuman from attacking Super Phoenix, his master. In the first round of the tournament, he quickly showed his power by slaughtering Kinnikuman Big Body's entire team, but tied on purpose with Cannonballer to allow Super Phoenix to be the one to fight Big Body. Mammothman next saw action in the six-man match between team Super Phoenix and Team Soldier. In a clash of titans he singled out Buffaloman and the two eventually engaged in a battle of possession of Soldier's Muscle Prophecy page. Buffaloman eventually took him out with a Buffalo Bomb but soon after fell to his death into the canyon below. When Mammothman regained consciousness he took the page and threw it into a torch, causing Soldier to begin disappearing. Later, after learning of Warsman's training to defeat the Big Tusks, Mammothman ambushed Warsman forcing him to drop out of the finals.
Mammothman's final battle was in another six-man match against Kinnikuman, Neptuneman (disguised as The Samurai) and Robin Mask. For the most part, Mammothman fought Robin, doing a number on the hero with his blood-seeking tusks. To make the fight "more interesting," Super Phoenix started to burn the pages of both of the choujin from the Muscle Prophecy book. The pages' destruction was akin to the choujin never having existed. Robin, master strategist as always, deduced the weakness of the tusks and spilled blood onto Mammothman himself. His tusks turned against him and impaled Mammothman. Robin defeated Mammothman with a Rope Work Tower Bridge. Both, however, disappeared with the immolation of their prophecy book pages, Mammothman crying his hatred for everyone assembled.
- Team Super Phoenix: Advance Guard (First Round)→ Second Guard (Semifinals)→ Second-in-Command (Finals)
- Choujin Hunter
- Intelligence Choujin
- Immortal Body
- Win/Loss Record
- O Pinchman (Powerful Nose Breaker)
- O Leopardon (Nose Fencing)
- O Golemman (Ghost Canvas)
- Δ Cannonballer (Double KO)
- X Buffaloman (Buffalo Bomb)
- O Warsman (Big Tusks)
- Δ or X Robin Mask (Rope Work Tower Bridge→ Double KO; This can be debated whether or not Robin would be considered the winner, simply for the reason that Robin was able to put away Mammothman, and did do so before his page was destroyed.)