Gorgoberos

Gorgoberos (ゴルゴべロス) is a novel exclusive kaiju that appeared in the Denkou Choujin Gridman: The Demon King's Counterattack novel in the September issue, while making a cameo appearance in Denkou Choujin Gridman: boys invent great hero.

Subtile: Fortress Super Beast (要塞超獣)

Denkou Choujin Gridman: The Demon King's Counterattack
Gorgoberos was summoned by Khan Digifier's younger brother in order to fight Gridman and Gridman Sigma as revenge for felling his elder brother.

Denkou Choujin Gridman: boys invent great hero
Gorgoberos appeared in the real world as a giant shadowy figure.

Powers and Abilities
Cannons : All along Gorgoberos' body are many cannons that he can use to attack.

Trivia

 * Gorgoberos is a Chouju, one of the first to appear outside of the Ultraman Ace.