Irys begins its life as a stone egg, sealed within a small underground temple in Nara village and guarded over by a family line named Moribe. Local legend said it was the resting place of a demon called Ryu-Sei-Cho. A stone of unknown origin is said to keep the demon dormant as long as it's not moved.
A young girl named Ayana Hirasaka, left an orphan by the 1995 Gamera and Gyaos battle and blaming Gamera for her parent's deaths, entered the cave on a dare and moved the stone. In the process she and the latest son of the Mirobe line discover both the egg and an amulet, similar to the one that linked Asagi to Gamera in the first film. The egg later hatched, produced a Baby Irys (ベビー·イリス?, Bebī Irisu).
Ayana gains a link to the creature via the amulet and feels a kinship with the creature, stating at one point "Gamera killed its family too"; driven by total hatred for Gamera, she raises Irys, naming it after her dead pet cat, in hopes that it will become strong enough to kill him for her. It was shown to have an affectionate nature, but this is shown alongside the sinister way it eats and, later in the film, the woodland animals it leaves dead.
It is not long before Irys it attempts to merge with Ayana, and her actions show she's willingly letting it do so, by sealing her in a cocoon. Moribe discovers her and cuts her free. She is then taken to a hospital. While Ayana is gone, Irys grows into a giant monster in the woods as it devours several villagers, including Ayana's adoptive parents and brother. Shortly, the monster grows into its adult form.
The J.S.D.F. quickly deploys and surrounds Irys as it sleeps, attempting to take it out with machine guns and bazookas. Some of the soldiers are killed before Irys takes to the sky and heads for Kyoto, where Ayana had been transferred earlier. The JSDF sends two F-15s in an attempt to shoot Irys down, but it is able to evade them and almost kills them. The fighter pilots are saved by the sudden arrival of Gamera, who engages Irys in a mid-air battle. The JSDF ends the battle by shooting at Gamera, which slows him down and allows Irys to continue on to Kyoto.
Soon, Irys lands in Kyoto and fights Gamera on land with Ayana watching and commanding to kill it. Irys manages to knock Gamera down for the count and then attempts again to merge with Ayana; when Moribe intervenes, the creature swats him aside and sucks her into its body against her will. While inside, Ayana realizes that she fueled Irys' destruction with her emotions - it was her hatred that led to the death of her adopted parents, and Super Gyaos instead of Gamera actually killed her parents. All seems lost until Gamera suddenly punches through Irys' armor and rips Ayana out.
Infuriated, Irys pins Gamera's hand to a wall with its spear hand and begins to absorb Gamera's energy. Its tentacles begin to form plasma balls, when Gamera quickly uses a plasma ball himself to sever his own hand. Irys fires the absorbed plasma balls at Gamera who uses his stump to turn the plasma into a plasma fist. Gamera then uses the fist to slice through Irys' chest, killing it.
The baby Irys has an armored, mouth-less head with small black eyes, and several long tentacles which sprout from a snail-like shell. It can absorb the life force of organic matter by stabbing them with its tentacle spears, leaving decayed corpses in its wake. The Behind The Scenes feature on ADV Film's DVD shows it was realized on-screen by a remotely-operated puppet.
The adult Irys is basically a bipedal creature with two hooved legs and retractable sword-like arms, topped by a head that resembles a pointed seashell. Its back is a mass of saw-edged plates, and from its sides spring four tentacles thousands of meters long. Each of these is tipped with a bony spearhead, from which Irys can fire a sonic beam similar to the Gyaos. Irys can still drain the life force from its victims, and in the case of Gamera it was able to absorb the monster's abilities and produce its own fireballs. Its chest region is also covered in glossy, bio-luminescent patches. The center patch can suck things into its body.
- Irys has a hard carapace similar to a turtle shell.
- Like Gamera, Irys has his own bead with which he can communicate with Ayana, strengthening him.
- Irys had four tentacles which could be used to absorb nutrients from other organisms. They were also used to deflect Gamera's fireballs.
- Each of Irys' tentacles is tipped by a bony arrow head shaped covering that can open. It can fire the same sonic beam as the Gyaos.
- Irys can form light emitting on it tentacles to serve as wings for flight at mach 9.
- Each of Irys' arms sport a retractable blade. The blades can pierce Gamera's body and absorb body fluids.
- Irys can analyze the DNA of any creature's body fluids it absorbs via its arm blades.
- Like the Gyaos and Gamera Irys can manipulate its own chromosomes to adapt and evolve to suit its environments. It can also adapt to incorporate and DNA it absorbed.
- Like Gamera, Irys has jet propulsion for flight, using plasma to fly as well as it wings. However it is more dependent on its plasma than its wings.
- The same technique used by the Gyaos, Irys can fire the Sonic Scalpel beam from any one of its Tentacles via their bony tips.
- After it had absorbed Gamera's DNA, Irys could then fire Fake Plasma from its tentacle tips.
- Irys, Gamera and Gyaos are the only three monsters in the Heisei series created by the Atlanteans.
This is a list of references for Irys. These citations are used to identify the reliable sources on which this article is based. These references appear inside articles in the form of superscript numbers, which look like this: