Gnome Cunning. You have advantage on INT, WIS, and CHA saves against magic.

Metamagic Adept. You gain 4 Sorcery points that can be used to change the structure of your spells.
Twinned Spell. You can spend sorcery points equal to a spell's level to target a second creature within range, so long as it cannot target more than one creature normally. 
Distant Spell. When you cast a ranged spell, you can spend 1 sorcery point to double the spell's range to a minimum of 30 ft. (also affects Touch spells)

Infestation. when you deal Piercing, Slashing, or Bludgeoning damage to a creature, it must succeed a DC 16 CON save or become Infested. An Infested creature falls prone and has disadvantage on Ability Checks, Attacks, and Saving Throws. an Infested creature can use its action to end the effect. 

Spellcasting. Zhurtah, The Black Plague, is a 6-level Druid. Its spellcasting ability is Wisdom (spell save DC 16, +8 to hit with spell attacks). Zhurtah has the following Druid spells prepared:
Cantrips (at will): Chill Touch, Minor Illusion, Poison Spray, Thorn Whip
1st level (4 slots):Cure Wounds, Entangle, Protection From Evil and Good, Inflict Wounds
2nd level (3 slots): Barkskin, Blindness/Deafness, Hold Person, Wither and Bloom, 
3rd level (3 slots): [Tooltip Not Found], Dispel Magic, Gaseous Form, Vampiric touch
5th level (Once per day): Danse Macabre

Symbiotic Entity. You can use Wild Shape to gain +24 temp HP, roll double damage for your Halo of Spores damage, and deal 1d6 additional Necrotic damage when you hit with Piercing, Slashing, Necrotic, or Poison damage. 

Wild Shape. You magically assume the shape of an undead beast twice per short rest. Max CR 1. You can remain in this shape for 3 hours or until dispelled. 

Thorn Whip. Ranged Spell Attack: +8 to hit, reach 30 ft., 1 target. Hit: 6 (2d6) Piercing damage. On a hit, the target must succeed a DC 16 CON saving throw or become Infested. 
Chill Touch. Ranged Spell Attack: +8 to hit, reach 120 ft., 1 target. Hit: 8 (2d8) Necrotic damage. 
Poison Spray. Ranged Spell Attack: DC 16 CON, reach 10 ft. 1 target. Hit: 12 (2d12) Poison damage. On a fail, the target becomes Poisoned until the end of their next round. 

Spells. Healing Word

Halo of Spores. You can use your reaction to deal 1d6 necrotic damage to one creature you can see when it moves into a space within 10 feet of you or starts its turn there if it fails a CON saving throw (DC 16).

Fungal Infestation. If a beast or humanoid that is Small or Medium dies within 10 feet of you, you can animate it as a zombie with 1 hit point. The zombie acts immediately after you and can only Attack.

Law of Spiders. When an ally within 60 ft. of you falls to zero hit points, Urstel can use their reaction to take (X) amount of Necrotic damage (ignoring Resistance and Immunity) and gift their ally temporary hit points equal to the damage taken.