Phancero

The Glitchbird Pokemon. Returning from Anniversary Crystal and Brown is this mysterious bird Pokemon which appeared at the end of both runs. Within the Haunted Mansion of Rijon is a portal that leads to a horrifying, glitched world. The bird appeared and teleported away. The Mob gave chase until it finally battled them, revealing its true identity as Phancero, a gigantic raven whose very existence defies the laws of reality as we know them. The Mob killed it, but were forced to start over again. It was eventually caught in the Master Ball.