Cordycep Ogre

Spore Burst. When the Cordycep Ogre is reduced to 0 hit points it bursts and released a cloud of red spores. Each creature within 10 feet of it must make a DC 12 Constitution saving throw, taking 10 (3d6) poison damage and become infected with the disease Flesh Rot on a failed save. While infected, the creature's flesh decays, they have disadvantage on Charisma checks and vulnerability to all damage.

Rend the Infected. The Cordycep Ogre has advantage to hit any creature infected with Flesh Rot.

Tree Trunk. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage. 

Spore Breath. (Recharge 5-6) The Cordycep Ogre breaths deep and unleashes a yellow miasma of spores into a 15 foot cone. Any creature caught in the cone must succeed a DC 12 constitution saving throw or succumb to a coughing fit and is incapacitated until the end of the Ogres next turn.