Ornismon

He is an Ancient Bird type Digimon.

Digimon Frontier
Long before the events of the series, AncientGreymon and AncientGarurumon sealed Ornithmon away on the Floating Continent. When the Digidestined reach it, they find that Murmuxmon has instigated a war between the Human and Beast Digimon on the continent in order to create enough strife to resurrect the evil bird. He succeeds, but is defeated by the combined might of the Legendary Warriors and the resurrected AncientGreymon and AncientGarurumon.