Robo Baltan

The Robo Baltan (ロボバルタン) is a comic-exclusive robot that appeared in the manga release of Ultraman Cosmos.

Telecoro Comic
Through the analysis of Alien Baltan Basical from 2001, the Robo Baltan was created by the militaristic defense force JADF (Joint Armed Defense Force) as their alternative to combat giant monster threats. The chosen pilot was Ryoma Makabe, Musashi Haruno's former high school classmate. Ryoma first piloted the robot to defeat the Chaos Bug, taking Cosmos' place in the television episode it appeared, but unbeknownst to others, a piece of Chaos Bug slipped into the robot.

At some point, while Robo Baltan parked within JADF's third base, the Chaos Header from Bug's destruction took over the robot and went rogue with Ryoma still inside as it attacked the entire base. Ryoma was willing to get himself killed but Cosmos saved him at the last minute before the Robo Baltan was finally scrapped.

Trivia

 * The Robo Baltan predated Hellzking as JADF's first attempt in creating monster-sized weapon. Additionally like the former, both went rogue as a result from an alien influence and was forced to be scrapped by the same Ultra (Cosmos) for good.
 * It also predated Cyber Mecha Baltan from Ultraman Festival 2016 as the first Alien Baltan android. Both robots likewise had an arm drill for their right hand.
 * As illustrated by the manga, the Robo Baltan possessed absurdly thin limbs and legs while its head closely resembles Basical's Neo Baltan form.