The Legendary Digimon Irridramon is rather odd and confusing. He is a Pyrosaur, yet his worst enemy is Giganodramon, and despite being an Irritator based Digimon, he takes an easy liking to Alberdramon, even though their relatives Spinomon and Tyrannomon hate each other to death. In a reverse syndrome of Alberdramon and Euoplodramon, Irridramon is equal level with Spinomon, despite both of their basis Dinosaurs being drastically different in size, with Irritator being rather tiny compared to the massive Spinosaurus. It's love interest in Alberdramon causes much anger in Giganodramon, who calls Alberdramon his sister, which is yet also ironic as Giganotosaurus and Albertosaurus were unrelated to each other, adding more to the relationship confusion. Not only that, but Irridramon calls Argendramon his older brother, even though Theropods and Sauropods are two different types of Dinosaurs. It was as if the Crest Guardians had one messed up series of relations with each other, or that they mirror other individuals...
Digimon World: Bronze and Cobalt Versions
Irridramon is faced in Cobalt Version during the main storyline in-order to obtain Giganodramon, and isn't seen again til after the main storyline, where it must be faced again to be obtained. Irridramon can be bred with Alberdramon to form a special type of Species Egg that can not only hatch into the parents' species, but can oddly also hatch into Angemon or Angewomon depending on the stats of the parents.