Heway (D&D 5E Monster)

Michael O. Varhola
Large monstrosity, neutral evil
Armor Class 12 (natural armor)
Hit Points 30 (4d10 + 8)
Speed 30 ft., Swim 30 ft.
STR                DEX               CON               INT                 WIS                CHA
17 (+3)            13 (+1)          14 (+2)           5 (−3)             12 (+1)           4 (−3)
Skills Perception 12, Stealth 13
Senses blindsight 10 ft., passive Perception 13
Challenge 2 (XP 450)
Contamination. A Heway's venom is powerful and persistent enough that if it dwells in or its dead body is dumped into a water source it will contaminate it, causing anyone who drinks the tainted water to suffer as much as 2d10 points of damage (DC 12 Constitution saving throw for half damage). Water flowing out of a contaminated area will become progressively less toxic the further it travels, causing as little as 2d8 to 1d4 damage and eventually none whatsoever (with a DC 12 Constitution saving throw to avoid damage altogether against these more dilute amounts of poison).
Squirt Venom. Ranged Weapon Attack: +3 to hit, range 20/—, one target. Hit: 11 (2d10) poison damage on a failed DC 12 Constitution saving throw, or half as much damage on a successful one.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 6 (1d6 + 3) piercing damage. 

The Heway is a large, often antagonistic snake that can squirt venom out of glands located near its eyes, giving rise to the popular description of it having a poisonous gaze. While the Heway can also bite prey in combat it does not have fangs and its teeth are not poisonous. 

Heways especially relish making their lairs in places like ruins or villages where everyone has been killed or driven off by them and their tendency to poison nearby water sources. Only one Heway will typically be encountered outside of its lair but in their home up to two might be encountered and, in this case, there is also a 30% chance that there will be 2-5 eggs. Most people consider these serpents to be malignant enough that they will simply insist on destroying their eggs, but there might be a market for them among particularly vile individuals (e.g., an evil spellcaster). Heways do not actively collect treasure but the valuables of those they have slain or chased away might be found in their lairs.