Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Unusual Nature. The zombie doesn’t require air, food, drink, or sleep.

Viral Aura. Any creature that starts its turn within 10 feet of the plague spreader must make a DC 15 Constitution saving throw. On a failed save, the creature is poisoned and can’t regain hit points until the end of its next turn. On a successful save, the creature is immune to this plague spreader’s Viral Aura for 24 hours.

Jack of All Trades. The bard adds an additional +1 bonus to any ability checks they make that they are not already proficient in.

Song of Rest. The bard can preform a song while taking a short rest. Any ally who hears the song regains an extra 1d10 hit points if it spends and Hit Dice to regain hit points at the end of the rest. The bard can confer this benefit on itself as well.

Spellcasting. The bard is a 9th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 15, +7 to hit with spell attacks). It has the following bard spells prepared:

Cantrips (at will): mage hand, minor illusion, vicious mockery

1/day each: greater invisibility, hold person, hypnotic pattern, legend lore, major image, polymorph 

3/day each: charm person, detect magic, faerie fire, healing word (2nd level)

Multiattack. The plague spreader makes two Claw attacks and one Peck attack or two Claw attacks and Casts a spell.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) bludgeoning damage plus 9 (2d8) necrotic damage.

Peck. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (1d12 + 7) piercing damage. 

Virulent Miasma (1/Day). The plague spreader releases toxic gas in a 30-foot-radius sphere centered on itself. Each creature in that area must make a DC 15 Constitution saving throw, taking 14 (4d6) poison damage on a failed save, or half as much damage on a successful one. A Humanoid reduced to 0 hit points by this damage dies and rises as a zombie 1 minute later. The zombie acts immediately after the plague spreader in the initiative count.

Bardis Inspiration (4/rest). One creature (other than the bard) that the bard can see within 60 feet gains a d8 bardic inspiration die. The creature can add the bardic inspiration die to one attack roll, ability check, or saving throw it makes within the next 10 minutes.

Silvery Barbs. 1 reaction, which you take when a creature you can see within 60 feet of yourself succeeds on an attack roll, an ability check, or a saving throw, you magically distract the triggering creature and turn its momentary uncertainty into encouragement for another creature. The triggering creature must reroll the d20 and use the lower roll.

You can then choose a different creature you can see within range (you can choose yourself). The chosen creature has advantage on the next attack roll, ability check, or saving throw it makes within 1 minute. A creature can be empowered by only one use of this spell at a time.

Undead Blessing (once per rest). The bard can cast Create Undead once per evening without requiring material components other than the corpses.