Aezt'ocan, the Last Guardian CR: 3
Medium dragon, lawful evil
Armor Class: 14 (Natural Armor)
Hit Points: 52 (7d8+21)
Skills: Perception +2
Damage Resistances: Fire
Senses: Darkvision 60ft, Passive Perception
Innate Spellcasting. Aezt'ocans innate spellcasting ability is Charisma (spell save DC 13). Aezt'ocan can innately cast the following spells, requiring no material components:
At will: mage hand
1/day: greater invisibility
Multiattack. Aezt'ocan makes two attacks: one with its bite and one with its tail.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) piercing damage.
Tail. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) bludgeoning damage.
Aezt'ocan is the last defender of an ancient yuan-ti laboratory. Created through alchemy, the creature has no need for food, water or sleep. Using its ancient knowledge and information of the lay of the ruin, it will use traps of the ruin to its advantage in an desperate attempt to stop any intruders from discovering Zachan the First.