Contamination Tracker

Symptoms of Contamination per level.
1 - None
2 - Hit points regained by expended hit dice halved.
3 - No hit points gained after a long rest.
4 - Damage dealt by weapon and spell attacks halved.
5 - Incapacitated. 
6 - Monstrous Transformation

 - Each time a character gains a contamination level, it rolls 1d6. If the result is equal to or less than the character’s current contamination level the creature gains a mutation (D20)
- Contamination levels cannot be reduced by resting or by known spells.
- A creature that gains 6 levels of Contamination gains a Monstrous Transformation and is now controlled by the DM.