Level 16 DiseaseTouch of Kyuss

Stage 0: The target recovers from the disease.
Stage 1: Initial Effect: The target regains only half the normal hit points when it spends a healing surge. If it dies, it rises immediately as a wretch of Kyuss.
Stage 2: The target loses two healing surges. If it drops to 0 or fewer healing surges, it dies and rises immediately as a son of Kyuss.
Stage 3: Final State: The target dies and immediately becomes a son of Kyuss.
Check: At the end of each extended rest, the target makes an Endurance check if it is at stage 1 or 2.
19 or lower: The stage of the disease increases by one.
20-24: No Change
25 or higher: The stage of the disease decreases by one.

Published in Monster Manual 3, page(s) 180, Dungeon Magazine 188.