If Tamurkhan's current body is slain, the true beast inside, a rotting maggot-like parasite, will immediately attempt to attack and possess a new host, gnawing its way beneath their flesh and consuming their brain and organs from within.
Source: Warhammer Armies Project: Unofficial 9th Edition (v2.2)
Feast of the Maggot LordURL Copied!
If Tamurkhan is slain in close combat, a special possession attack is made against the model that delivered the final wound to Tamurkhan. If Tamurkhan's death occurs as a result of shooting or other means, the attack will be made against the nearest eligible model (friend or enemy) within 6". If multiple models fall into this category, Tamurkhan's player chooses which to attack.
Both players roll a D6 and add the Weapon Skill value of their respective models. If the result is a draw, roll again until one side wins. If Tamurkhan's player wins, the victim is killed outright and their body is possessed. From then onwards, Tamurkhan takes over the victim model, which is detached from its unit and placed l" away from it. The model is now controlled by Tamurkhan's player for the rest of the game exactly as if it were their own character model. Only Infantry and Monstrous Infantry models are eligible to be possessed. Tamurkhan cannot take possession of a model with the Animated Construct, Daemonic, Ethereal, Forest Spirit or Vampiric special rule.
The characteristics of the new body possessed body uses the Possessor profile, but with the following changes: -1 Movement, +1 Toughness, +1 Wounds, -2 Initiative. Strength and Attacks is equal to the possessed model's stats. Note that any wounds they previously suffered are still in effect. So, for example, if a model has only one wound remaining when it is possessed, it now has two wounds including the +1 for the Possession modifier.
Tamurkhan now uses any weapons or armour the victim had (including magical types), discarding both his own and any other equipment the victim has. Likewise, any ability the victim had as a Wizard is lost. This includes any special rules the victim formerly used other than their unit type, Natural Armour and Regeneration.
If no eligible model is available or the possession attack fails, Tamurkhan is killed outright. Also, Tamurkhan's power cannot save him if he is destroyed by an attack which causes a model to be slain outright rather than causing wounds.