The sidekick of Kinkotsuman.
Iwao is the henchman of Kinkotsuman and a source of comic relief in the series. He initially appears as a villain that is defeated by Kinnikuman and later becomes a part of Kinkotsuman's entourage, but eventually he switches sides and becomes a good character on the side of justice.
Iwao (イワオ) is a rock Kaiju who first appears at an amusement park and is subsequently defeated by Kinnikuman.
Initially, Natsuko wishes to do a story about Kinnikuman, but - when a fight breaks out - Terryman appears to resolve the conflict.  Terryman flirts with her, Kinnikuman calls her a 'slut'; she storms away and is kidnapped by Iwao. Kinnikuman saves her, while she takes many photographs. 
He returns when Kinnikuman is being interviewed by Natsuko and plans to beat him up in front of her and ruin his image. His first attempt is interrupted by Kappatron so he tries to take Natsuko hostage, but he is still easily defeated by Kinnikuman. He then takes on the role of Kinkotsuman's sidekick and helps him with all of his attempts to destroy Kinnikuman. They seemingly turn good after the Chojin Olympics, but return as villains during the American Tag Tournament.
They make their debut at the opening ceremonies of the American Chojin Tag Tournament.  They promise to Kinkotsuman that they will not let him down, but soon a battle royale breaks out among the contestants; Black Shadow starts to attack Iwao, despite being on the same side.  Their first match is set to be against the Blood Illusions, which they knock The Machineguns out of the way in order to fight their opponents. 
The Rugged Brothers charge forward, but Devil Magician knocks Iwao out of the ring, before the Blood Illusions' focus their attentions on the Black Shadow. They rip off his arms in a blood-filled scene, before forcing the "8 Defence" on him, which - as Black Shadow can't give up (due to having no mouth) - they are able to completely dismember him. They toss his head at Jean Steamboard, while Kinkotsuman grieves his death. 
In the anime, the two of them eventually join up with Detective Gobugari and act as Kinnikuman's main cheering squad.
Speech & Quotes
Iwao is not that bright and frequently copies Kinkotsuman's laugh and speech pattern. For example, he frequently says dawasa (だわさ) (which Kinkotsuman often ends his sentences with) as a single sentence, seemingly meaning "I agree". This annoys Kinkotsuman and often prompts him to bop Iwao on the head. Iwao also refers to Kinkotsuman as Sensei.
- 1,000,000 Yen Quiz Winner (Tag?)
- Kinkotsuman's Underling
Win/Loss Record (Tag)
- X Blood Illusions (8 Defence)
|Iwao, Nachiguron, Okamaras, King Ton, Black Shadow, Ukon|
|Sprinter Sword, Gorizaemon, Gonta, Franky, Octopus Dragon, Eragines, Nessie, Daibutsura, Bullgoras, Abdullah, Apollo the Giant, Bottomless Alien, Brutal Alien, Alien Sheik, Tendon, Monster Turkey, Miss Karasu, Mammora, Dai King|