Universal Rule.
The model gains One of a Kind and +1 Health Point.
The roll for the number of hits from its Stomp Attacks is subject to Maximised Roll.
In addition, replace the rules of Devour with (changes from original version in bold):
For each Health Point loss the model causes with Close Combat Attacks against enemy units, roll a D6 at the end of the Initiative Step. For each rolled 4+, the model gains +1 Health Point. When the model has 20 Health Points or more, all units within 12″ immediately suffer 2D6 hits with Toxic Attacks, and the model is removed as a casualty