|Home world:||Different dimension|
|First appearance:||Ultraman Cosmos episode 24 "Warm Memories"|
|Weight:||56 000 t|
Subtitle: Electromagnetic Demon Beast (電磁魔獣 Denji-maju?)
- Height: 60 m
- Weight: 56 000 t
- Origin: Different dimension
One day at the Kanna City, a strange phenomenon happened where recently, electronic appliances stops working. The monster named Gragas was the one who behind this. However, he was only visible to a boy whom tried to warn everyone but nobody awares him except Ayano where tried to tell Ayano about this even in various places. It was revealed that the boy was actually in coma and his spirit separated from his body while trying to warn everyone on Gragas threat but Ayano was the only one that can see him due to the fact that they had met each others as a child. With Gragas appeared again, enlarged, Musashi transforms into Cosmos and put into a fight. With Cosmos Corona Mode gained the upper hand, Gragas "surrendered" as Cosmos decided to leave him but the monster instead attacked the Ultra again. Enraged, Cosmos put an end to him via Corona Blazing Wave.
- Suit actor: Kazunori Yokoo
Powers and Abilities
- Invisibility: Gragas can turn himself invisible but this eventually visible to spirits.
- Size Change: Gragas can grow into giant size.
- Electromagnetic Field: Gragas can create a field which disable communication devices.
- Tentacles: Gragas can unleash two tentacles to latch on the opponent.
- Electric Shock: Then, Gragas can sent the opponent a electric shock.
- Electric Bombs: Gragas can fire electrical bombs from his hands.
- Flight: Gragas can fly as means of travel.