Gudis is an alien monster and the composition of destructive viruses known as Gudis Cells. His Gudis Cells can consume other life forms, replace their cells with Gudis Cells to make them a part of Gudis. Gudis's ultimate goal is to consume all living things in the universe.
Ultraman is given the mission to destroy Gudis. He fought with Gudis on Mars, successfully blew up Gudis's body with his most powerful attack "Burning Plasma". However, Gudis's body collapsed into countless Gudis Cells instead of permanent death. His cells hided on earth and infected many monsters left for Ultraman to fight.
After consuming enough life energy, Gudis revived on earth as Gudis II and claimed himself as a God. Even Ultraman was absorbed into Gudis's body. However, Ultraman's human host Jack Shindo told Gudis that parasitizing on other life forms to sustain himself is meaningless and pathetic. Gudis became angry and lost control, allowing Ultraman to break out from his body and permanently destroy all Gudis Cells at once.
Tentacles: Gudis has powerful tentacles performing immersive physical strength.
Flight: Gudis can fly freely in the atmosphere and space. He is seemingly able to fly beyond light speed in space.
Infection: Gudis can infect other life forms with Gudis Cells.
Immortality: Gudis cannot be permanently killed unless all of Gudis Cells were destroyed completely.
Disasters: Gudis Cells can bring disasters, including disease, pollution, and natural disasters, seemingly as supernatural power.
Gudis II possesses equal abilities with Gudis and gains more.
Absorption: Gudis II can absorb different kinds of energy. He absorbed energy from lavas to reshape his body, also absorbed Ultraman's attacks.
Eye beam: Gudis II can shoot red beams from his eyes, which are devastating to his foes.
Telekinetic: Gudis II can move objects with telekinetic power.