The Gappas (ガッパ?) are a species of ancient reptilian bird Gappakaiju. Two adult Gappas, male (雄ガッパ?) and female Osu Gappa (雌ガッパ?) and their Mesu Gappajuvenile son appear in the 1967 Nikkatsu kaiju film, Gappa.
In ancient times, the Gappas would fight other monsters for survival. They were already present when the Earth was still an interstellar cloud. This suggests Gappas originate in outer space.
- Main article: Gappa/Gallery.
All three of the Gappas share common characteristics, being based on various reptiles and birds, such as eagles and hawks. Overall, they resemble enormous bipedal Griffins. As seen with the two adults seen in the film, the species is sexually dimorphic. The male is 60 meters in height and female is 55 meters. The female has a smaller head crest and has a flatter face compared to her mate. Their scales are triangle-shaped, and their eyelids are reverse to that of humans. Gappas' wings are unlike those of birds; these wings are actually evolved ribs.
An expedition to Obelisk Island by Mr. Funazu uncovers a baby monster, who hatches from an egg nearby giant bones beside a underground lake below a sacred temple. The natives plead with the skeptical scientists not to take the baby away, lest it anger the baby's parents. Sure enough, they take the baby away, and soon, inside the caverns, its two parents rise from the underground waters beneath the volcano, destroying everything in their path. Saki, the only survivor, is rescued by an American navy fleet and brought back to Japan.
The parents storm across Japan, destroying all in their wake, but their assault ceases once they recover their child. Mercifully, they relent, and depart to return to Obelisk Island.
The Gappas are very ancient species. They were already present when the Earth was still an interstellar cloud. They have fought many monsters since that time and this indicates there have been various monsters including Gappas capable of surviving in space and during planet formations, and Gappas are, one of, if not the most, powerful of those. The fact that female Gappa preyed on an octopus when the pair appeared on Atami indicates Gappas might feed on aquatic life. Female Gappa hunted the octopus to feed the juvenile, and the juvenile has never feasted on the meats humans had prepared.
Their influences on planet Earth and life forms including humans were vast; base elements from Gappas' internal organs for charging electricity melted into the sea water during Earth's formation, and this caused today's sea water to be salty.
Despite their destructive capabilities, Gappas are sentient, intelligent, and generous species by nature and would not attack meaninglessly. They deeply cares their families and will do anything to take back their children. Although the pair caused severe destruction on civilization in Japan, that was for taking back their child.
The Gappas are more sensitive to sounds than other known reptiles.
- The Gappas can fly at mach 6.
- The Gappas have an underwater speed of 150 knots.
- The Gappas can perform a destructive force of 2 million hps.
- The Gappas' wings can emit hurricane-force winds.
- The Gappas can cause tsunamis or storm surges by their wing powers.
- Adult Gappas can fire Radiant Heat Beam (放射熱光線?) (being described as "equals to death ray" in the film) from their mouths that can burn and melt anything it touches. This ability makes Gappas immune to poisons. Hōshanetsu Kōsen
- The Gappas emit bioluminescence from eyes (blue-white underwater and yellow on land).
- Female Gappa has pearl-like substances likely within her legs. This substances will cause humans blind.
- Juvenile Gappa's body is electrified and causes electric arcs/sparks whenever metals are attached to the body.
- This indicates that adult Gappas can possibly emit electricity.
- Gappa was based on a famous yokai Kappa and images of Karura aka Garuda and Karasu Tengu were added.
- The film story was partially based on 1961 film Gorgo with some similarities with Toho's 1961 film Mothra and Daiei's Gamera and Daimajin.
- Gappas caring natures towards family are similar to that of oceanic birds such as penguins.
- Tsuburaya Productions originally had an idea of a space bird monster that protected Earth in times of need, called Bemlar. The 'Bemlar Birdman' shares many traits with the Gappa, and caused rumors of being sold to Nikkatsu Corporation. However these rumors are false, as the design was recycled for another Tsuburaya monster called Hydra. Thus, Hydra bears a resemblance to the Gappas as well, although he is completely feathered.
- English version of the DVD cover shows a monster with drastically different appearance from real Gappas while this "Gappa" partially fits to the legends of kappas at least on general appearance.