Swarm. The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny snake. The swarm can't regain hit points or gain temporary hit points.
Actions
Bites. Melee Weapon Attack: +6 to hit, reach 0 ft., one creature in the swarm's space. Hit: 7 (2d6) piercing damage, or 3 (1d6) piercing damage if the swarm has half of its hit points or fewer. The target must make a DC 10 Constitution saving throw, taking 14 (4d6) poison damage on a failed save, or half as much damage on a successful one.
How many swarms of poisonous snakes for a fight?
A swarm of poisonous snakes is worth 450 XP. Using the 2024 encounter budgets (SRD 5.2), this is how many swarms of poisonous snakes fit each difficulty for a party of four characters of the same level. A dash means even one would be over the budget.
Party level
Low
Moderate
High
2nd
—
1
1
3rd
1
2
3
4th
2
3
4
5th
4
6
9
6th
5
8
12
7th
6
11
12+
8th
8
12+
12+
9th
11
12+
12+
Budgets add up every monster’s XP, so you can swap some for other creatures of the same total. Try other party sizes and mixes in the encounter calculator.
How the swarm of poisonous snakes compares at CR 2
Against the 42 other challenge 2 monsters in the SRD 5.1, the swarm of poisonous snakes has more hit points than 12 of them, which makes it a little frailer than most at its CR. See every CR 2 monster.
Statistic
Swarm of Poisonous Snakes
CR 2 average
Armor Class
14
12.9
Hit points
36
47
Best attack bonus
+6
+5
Best save DC
10
12
2024 stat block: Swarm of Venomous Snakes
The 2024 Monster Manual revised the swarm of poisonous snakes, and the SRD 5.2 carries the new stat block. What changed:
It’s called the Swarm of Venomous Snakes in the 2024 rules.
Swarm. The swarm can occupy another creature’s space and vice versa, and the swarm can move through any opening large enough for a Tiny snake. The swarm can’t regain Hit Points or gain Temporary Hit Points.
Actions
Bites. Melee Attack Roll: +6, reach 5 ft. Hit: 8 (1d8 + 4) Piercing damage—or 6 (1d4 + 4) Piercing damage if the swarm is Bloodied—plus 10 (3d6) Poison damage.
