Spellcasting. The mage is a 5th-level spellcaster that uses Intelligence as its spellcasting ability (spell save DC 14; +6 to hit with spell attacks). The mage knows the following spells from the wizard’s spell list:
Cantrips (at will): Acid Splash, chill touch
1st Level (4 slots): Mage Armor, Ray of Sickness
2nd Level (3 slots): Blindness/Deafness, Mirror Image
3nd Level (2 slots): Fear, Vampiric Touch
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.
Slam. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) bludgeoning damage.