From the blog "The Aksha'i Cruentes - A World Eaters Crusade Blog"

For weeks, Kratus's physical form had been in flux. His movement was not a fluid motion, as if viewed through a pict feed at a low framerate. In the blink of an eye, Kratus would appear in a totally different position; blink again, and he might appear to have never moved, as if he were totally disconnected from reality.   Kratus has offered many a worthy skull to the Blood God's throne, felling skilled warriors and titanic Knights alike. It was the foul xenoform known as the Salt Wyrm