Edit
A Holy Knight Digimon. Craniummon is a colossal undead knight-like being, but despite its appearance it is in fact one of Yggdrasil's most loyal servants. It wields a massive double-bladed broadsword named the Duo Solar Spear.
It is a member of the Royal Knights, and carries the title of "Holy Knight of Loyalty" (忠誠の聖騎士, Chuusei no Hijiri Kishi).
Craniummon is referred to as Craniamon in English material.
Nobody here but us chickens!