Gigan is a kaiju from Toho's Godzilla franchise who first appeared in Godzilla vs. Gigan. Gigan is a space monster resembling a species of reptile who was turned into a cyborg by the Nebulans. Gigan sports a huge buzzsaw in its frontal abdominal region, large metallic hooks for hands, and a birdlike beak. Gigan is considered one of Godzilla's most brutal and violent opponents, and the first kaiju in the Toho sci-fi series to make him noticeably bleed. Complex listed the character as No. 2 on its "The 15 Most Badass Kaiju Monsters of All Time" list.

Kaiju is a Japanese term that is commonly associated with media involving giant monsters. A subgenre of science fiction, it was created by Eiji Tsuburaya and Ishirō Honda. The term can also refer to the giant monsters themselves, which are usually depicted attacking major cities and battling either the military or other monsters.