Excalipurr is the 4th and final part of the Grand Architect, Zenus. He also provides him with speed and agility.
He was one of the 4 parts of Zenus, when Corvus's dark energy beam smashed through the Realm of the Almighty and split them up, sending them deep down into the grottoes. His most recent memories where that he was in the Palace of the Almighty with Celestria, arguing about whether the mortals deserved to live or not. There was then a flash, and he awoke in the depths of a grotto.
Excalipurr can be found in high level grottoes (levels 70-99)
Excalipurr is a pun of Excalibur, the magical sword wielded by King Arthur in the well-known English folk-tale King Arthur and the Knights of the Round Table