Twins with Laambo, he is even more violent than his brother. The two have committed countless crimes from planet to planet, and their infamy is known throughout the universe.
Like his brother, war is Walltha's reason for existence. Walltha's tactics always involve sending in his command unit, P-3800, rushing straight towards the enemy. This unit composed of some of the best fighters in the GEATHJERK army. Owing to the savage tribe he comes from, he is bloodthirsty and merciless, and feels no anguish for losing allies in war - even his brother.
He uses a tuned up custom version of the bipedal assault weapon Gah-Goojin, fighting beside his troops on the front lines. Watching how happily he annihilates everything in his surroundings is said to bring terror to even his fellow GEATHJERK officers.
Walltha resembles a large bipedal lizard with black scales. He appears to have a severe case of under-bite, though Laambo shares this quality too, implying it might run in his family or be a part of his species natural appearance. Like Laambo Walltha also has flames emanating from his back, though unlike Laambo Walltha's flames are blue. Fire also emanates from Walltha's chin, giving the appearance of a beard. His outfit consists of blue garments with gold and neon blue accents. Along with a pair of spiked pauldrons, spiked gloves and 3 medals on his chest.
After the heroes successfully secure the Goddess Statue, hijack the Gah-Goojin attacking it and escape Lowrule, Walltha appears before them and announces himself as the brother of Laambo. He claims that he simply serves Jergingha and does not want "revengeance" for his brother, and then jumps into his personal vessel, the Wallgah-Goojin. He challenges the heroes to a fight, who accept, piloting the recently-captured Gah-Goojin as a battle mech. After the Punch-Out!-like boss battle is over, the heroes hijack his vessel and attack him physically.
After he has been dealt a sufficient amount of damage, the heroes escape on the Virgin Victory, with an angered Walltha in hot pursuit. After evading him for a few minutes, the Virgin Victory flies safely out of the volcano and Wonder-Green Unite-Guns the Wallgah Goojin's head off before it can fire its death ray. It is then engulfed in the eruption. Before his death, he exclaims "How could you puny humans have possibly defeated me?!", which is the same thing Laambo had said right before he died. As his mech explodes in the column of lava, wiping Walltha right out of existence, Wonder-Blue reminds him to find a way to make up to his brother "...in Hell!".
- Despite being twins, Walltha and Laambo are polar opposites in both personality and style. Unlike his brother, Walltha is more calm, cool, and collected and is not driven by his emotions and is willing to sacrifice his own men and his own brother to get what he wants. Walltha also wears a cleaner and well-cared-for outfit that is blue in color, matching his flames.
- Walltha's personality is similar to Vergil's from Devil May Cry.
- When Walltha is told of his brother's death, he claims that he will not fight for "revengeance", keying the title of another Platinum Games work, Metal Gear Rising: Revengeance
- Walltha wears three GEATHJERK Medals on his uniform, possibly to mark his rank as Third Officer.