Small dragon, unaligned

Armor Class 17 (natural armor)
Hit Points 33 (6d6 + 12)
Speed 20 ft.

15 (+2) 8 (-1) 15 (+2) 2 (-4) 12 (+1) 11 (+0)

Skills Perception +3, Stealth +1
Damage Immunities poison
Condition Immunities poisoned, prone
Senses darkvision 60 ft., passive Perception 14
Challenge 8 (3,900 XP)

Special Traits

  • Contamination. The basiliskos emits an aura of corruption 30 feet in every direction. Plants that aren’t creatures wither in the aura, and the ground in it is difficult terrain for other creatures. Any creature that starts its turn in the aura must succeed on a DC 12 Constitution saving throw or take 14 (4d6) poison damage. A creature that succeeds on the save is immune to this basiliskos’ Contamination for 24 hours.
  • Corrupt Water. At the start of each of the basiliskos’ turns, exposed water within 30 feet of it is befouled. Underwater, this effect lightly obscures the area until a current clears it away. Water in containers remains corrupted until it evaporates. A creature that consumes this foul water or swims in it must make a DC 12 Constitution saving throw. On a successful save, the creature is immune to the foul water for 24 hours. On a failed save, the creature takes 14 (4d6) poison damage and is poisoned for 1 minute. At the end of this time, the poisoned creature must repeat the saving throw. On a failure, the creature takes 18 (4d8) poison damage and is poisoned until it finishes a long rest.
  • Keen Smell. The basiliskos has advantage on Wisdom (Perception) checks that rely on smell.
  • Serpent Ward. Any reptile that attacks the basiliskos and can hear its hiss suffers advantage on all attack rolls against it.
  • Swamp Camouflage. The basiliskos has advantage on Dexterity (Stealth) checks made to hide in swamp terrain.


  • Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 6 (1d8 + 2) piercing damage.
  • Poison Breath (Recharge 5-6). The basiliskos spits acid in a 15-foot cone. Each creature in that area must make a DC 9 Dexterity saving throw, taking 10 (3d6) poison damage on a failed save, or half as much damage on a successful one.


This serpent is not more than 12 inches long and adorned with a bright white marking on the head like a sort of diadem.

A basiliskos is a reptilian monster that can kill living creatures with a mere gaze. A basiliskos usually has a dull brown body with a yellowish underbelly.

A basiliskos relies on its breath weapon, biting only when opponents come within reach. These creatures tend to spend most of their time lying in wait for prey, which includes small mammals, birds, reptiles, and similar creatures.

Curse of Cyrene. Basiliskos are primarily found in Cyrene. Their ability to corrupt water is particularly deadly as they are common in deserts, ensuring parched travelers die of thirst before they even encounter the beast directly.

Section 15: Copyright Notice

5E RPG: Ancient Adventures. Copyright 2020, Mal and Tal, LLC; Author Michael Tresca.

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