Jiger is a horned quadrupedal reptile somewhat reminiscent of the extinct dinosaur Triceratops. It however has a sail on its back, and has two nose horns and a single forehead horn.
After the statue is removed, Jiger makes her first appearance and gets Gamera's immediate attention. The first of several fights ensues, and Jiger wins by shooting projectile quills from her face. The quills impale Gamera's arms and legs, piercing all the way through and preventing Gamera from withdrawing his limbs into his shell and taking flight. To make matters worse, Gamera is on his back and cannot move. He pulls himself up with his tail using a large rock and then removes the offending quills from his limbs and is finally able to fly after Jiger.
Meanwhile, Jiger is actively seeking the statue, because it is making a horrible ringing sound that is causing her tremendous pain. Jiger lets nothing impede that hunt as she splits two ships in half and starts tearing through Osaka. Scientists are beside themselves as Jiger displays another weapon: a heat ray that vaporizes not only flesh but entire city blocks. The J.S.D.F. does make a token effort to kill the monster, but her quills knock down the F-104 fighters, ending that involvement.
Gamera returns for round two as the fight is witnessed by several children. Gamera knocks Jiger around and appears to have the upper hand until Jiger pulls Gamera to her. Jiger extends a stinger from her tail and inserts the barb into Gamera's chest, laying an egg inside his lung. Gamera staggers away, roaring in agony. Finally, he barely makes it to the bay and his body turns a chalky white color, almost like ice. Gamera is presumed to have been killed at this point as Jiger heads straight to the World's Fair. Jiger finally obtains her goal of the statue, and throws it into the ocean, ending the painful noise.
The scientists were checking out possible causes of the noise, as it affected humans, causing temporary insanity. The children convinced them to do a medical exam on the comatose Gamera, where it's discovered that there's a dark spot on one of his lungs. One of the scientists served as a zoo director and realized that the spot might not be a fast spreading cancer, but actually a Baby Jiger growing in Gamera's lung. An operation was needed to remove the threat, so the children took the initiative by taking a walkie talkie and a mini-sub. Communication is established with the kids and they enter Gamera through his open mouth, and after almost going into his stomach, they arrive at the problem lung. The children are able to exit the sub and walk around in the lung. There, they discover the baby.
The baby looks like its mother, except that instead of shooting quills, the baby squirts sticky goo. But, the baby has a weakness just like its mother: white noise. The kids discover this is actually a fatal weakness and manage to kill the baby using static from their radio. They leave Gamera's body and report their findings to the scientists. They rig up large speakers to keep Jiger at bay, as well as figuring out that power would have to also be run into Gamera, who cannot recover on his own. The children make a final trip inside Gamera to hook up a set of power lines directly to his heart.
Jiger is kept still by the speakers playing the white noise. It's not enough to kill Jiger, but buys enough time for the other plan to start. Gamera is subjected to high voltage shock before the electrical grid overloads. It's enough that Gamera revives on his own.
Gamera flies over to the World's Fair for the final battle. Jiger tries every weapon she's got, but Gamera merely retracts into his shell when the quills start flying. Jiger then uses her heat ray. It doesn't affect Gamera's shell or even skin. Gamera body-slams Jiger several times from great heights, but Jiger isn't really affected. However, it buys Gamera the time needed to go into the ocean to retrieve the statue from the sea floor. Jiger, enraged by the statue's return attempts to impregnate Gamera again. Gamera uses the statue to crush Jiger's tail, destroying the stinger. Gamera taunts Jiger with the statue, who tries in vain to catch Gamera and retrieve the statue. Gamera finally ends the fight by throwing the statue at Jiger, which embeds itself in Jiger's skull, killing her.
Jiger can shoot deadly impaling quills from her head. She can also fly by means of jets in the back of her head, she can fire a heat ray that is capable of dissolving buildings and ships and even people, she has a suction ability that allows Jiger to pull things towards her, and her tail ends with a stinger. Despite not being actually venomous, the stinger is used by Jiger to reproduce in ways similar to insects, in that it can be used like an ovipositor to implant an egg into a victim that feeds off the victim's blood when it hatches. In addition, Jiger can put her eggs inside other creatures, such as Gamera, which parasitically lives off the host up until it hatches.
Jiger can not stand the Devil's Whistle and it causes her great pain. The statue was specifically built to keep Jiger at bay.
- Main article: Jiger/Gallery.
- Jiger is the first female monster in the Gamera series.
- The way Jiger implants a parasitic egg inside a living host is reminescent of parasitoid wasps, as well as the Xenomorphs from the film "Alien".
- Jiger makes a cameo appearance in a Franklin the Turtle cartoon episode, along with some other Gamera villains when Franklin is imagining monsters in the dark.
- A similar event occurs in the movie Pacific Rim, where a team is sent inside a kaiju's body and encounters a baby kaiju inside, which attacks them.