Alector

Echolocation. The bat can't use its blindsight while deafened.

Keen Hearing. The bat has advantage on Wisdom (Perception) checks that rely on hearing.

Bite. Melee Weapon Attack: +2 to hit, reach 5 ft., one creature. Hit: 1d8 piercing damage.

Screech. Ranged Attack: +3 to hit, 30 ft. cone. All creatures within the cone must make a constitution saving throw (DC 15). On a failed save, the creature takes 3d4 psychic damage. On a successful save, the creature takes half as much.The bat becomes aware of your location.

Spillover. Ranged Attack: +2 to hit, 6 ft. cone. All creatures in range must make a constitution saving throw (DC 18). On a failed save, they are infected with one of several diseases. An effected creature will take damage and be effected by a condition depending on the disease. Roll 1d4 to determine which virus infects each target.

1. SARS: 4d4 poison damage each turn. Possibility of spread for 14 days.
2. Ebola: 4d6 poison damage each turn. Possibility of spread for 2 days.
3. Nipah: 2d4 poison damage each turn. Chance of Unconscious condition on a failed constitution saving throw each turn (DC 10). Possibility of spread for 7 days.
4. Hendra: 2d6 poison damage each turn. Possibility of spread for 7 days.

Each disease continues for the duration, with close contact spread possible for each of them. They deal the same roll of damage each day.