Comments from the writer: Even the low creatures of the earth need a protector, and they respond in kind! Summon a swarm of creatures with your Wild Shape with this subclass for druid we designed by request back in 2016 and updated for Valda’s Spire of Secrets.
Druids of the Circle of Vermin, sometimes known as Vermin Lords, find their source of power in the lowliest of creatures: insects, rats, spiders, and other pests. Unmistakably, your coming is signaled by the scrambling of little claws and the cawing of the crows. You hold legions of these creatures at your command, ready to swarm, bite, and claw, and you can become one of them, to walk among your innumerable children.
Lord of the Low
Starting when you choose this circle at 2nd level, you can expend a use of your Wild Shape feature as an action to magically summon a swarm of rats in your space. The swarm vanishes after a number of hours equal to half your druid level (rounded down), if it drops to 0 hit points, or if you use this ability to summon a new swarm.
The summoned swarm is friendly to you and your companions. Roll initiative for the summoned swarm, which has its own turns. It obeys any verbal commands that you issue to it (no action required by you). If you don’t issue any commands to it, it defends itself from hostile creatures, but otherwise takes no actions.
While the swarm is in your space, you have a +2 bonus to AC and, when you take damage, you can choose for the swarm to take damage instead of you.
Starting at 6th level, you can summon a swarm of bats, swarm of insects, or swarm of ravens, and starting at 14th level, you can summon a swarm of poisonous snakes.
Infested
At 2nd level, insects and rodents inhabit every nook and cranny of your clothes and gear. Whenever a creature within 5 feet of you hits you with an attack, these vermin retaliate, dealing 1d4 piercing damage to the attacker. Additionally, the creature subtracts the piercing damage dealt from the next attack roll it makes before the end of its turn.
Tremorsense
By 6th level, vibrations in the ground echo through its ants and earthworms, and by extension, you can sense them. You gain tremorsense, the ability to detect and pinpoint vibrations, with a range of 10 feet. To use this sense, you and the source of the vibrations must be in contact with the same ground or substance. This sense can’t be used to detect flying or incorporeal creatures.
Plague Carrier
Beginning at 10th level, your constant close proximity to disease-carrying creatures has not only inoculated you to their diseases, but also allowed you to act as a vector of plague. You are immune to diseases and the poisoned condition. Whenever you would normally make a Constitution saving throw to avoid contracting a disease or the poisoned condition, you can instead become a carrier of that disease or poison. You can only be a carrier of one disease or poison at a time, and you can only carry it for up to seven days.
As a reaction when you take damage from a creature you can see within 5 feet of you, you can transfer a disease or poison you are carrying to that creature, which must make a Constitution saving throw against your spell save DC. On a failure, the creature contracts the disease or poison, and you are no longer a carrier of it.
Swarm Master
Starting at 14th level, whenever you use your Lord of the Low feature to summon a swarm, you can summon two swarms instead of one.
