There were originally two Rodans, male and female (Rodan, 1956). Both apparently perished in the eruption of Mount Aso in southern Japan, but one survived to fly and fight again in Ghidorah, the Three-Headed Monster (1964). Like Mothra, Mechagodzilla, and King Ghidorah, Rodan is one of the four monsters updated for the Heisei series (1993) where he became a pteranodon mutated by radiation. Fire Rodan is larger and heavier than original Rodan, and is capable of emitting a uranium heat beam.
In Rodan, two eggs, one male and the other female, were unearthed and awakened by mining operations in Kitamatsu along with a swarm of prehistoric insects called Meganulons. After devouring several people and reducing Sasebo to ruins, one Rodan is maimed in a bombardment of their nest in Mount Aso and falls, apparently fatally, into a volcanic eruption triggered by the attack. The other grief-stricken Rodan flies into the volcano to join the first. Rodan initially fought against Godzilla, but it has since become long-time and big help when Godzilla needs support to fight many opponents.
Rodan helped Mothra turning back King Ghidorah's first invasion of Earth, and the outsized pterodactyl later accompanied Godzilla to Planet X for a rematch with the three-headed monster. Ultimately, Rodan wound up in residence on Monsterland, his flight restricted by magnetic force fields, but seemingly happy on his island home in the company of his fellow monsters.
In his later embodiment, Fire Rodan helped Godzilla to protect a baby Godzillasaurus and defeated the U.N.'s flying Garuda battlecraft. Dead-wounded by MechaGodzilla, Fire Rodan purposely landed on the corpse of Godzilla. His discorporating body released a blizzard of radioactive energy that brought Godzilla back to life, allowing him the ultimate triumph against Mechagodzilla.
After being defeated and left for dead by Godzilla, Rodan was revived by the psychic song of an ancient plant that had covered Baby Godzilla's egg. Godzilla's radiation mutated Rodan, changing his colors from brown and tan to brick red and light yellow/gold. Fire Rodan also gained a purple colored atomic breath similar to Godzilla's. His beak is powerful enough to break through boulders.
Like the Showa version, Rodan seems impervious to Godzilla's breath but only to an extent. Being hit several times and not seeming affected until later in the battle. In the 2004 film, Godzilla: Final Wars, Rodan is used as a weapon of destruction by an alien race called the Xiliens via mind control. He appeared alongside an all-star cast of classic Showa monsters, as they wreaked havoc on the major cities of the world and were sent to fight the mutant dinosaur Godzilla.
Rodan attacked New York City, and later fought alongside the guardian monster King Caesar and Anguirus to fight Godzilla, only to be defeated near Mount Fuji, but Godzilla did not kill them; Toho's way of paying homage to the times in the past all three had fought by his side.