Circle of the Hive

Some druids are rumored to be able to not just shape shift into a single animal, but into an entire swarm. Insects might not be the strongest or most durable, but they sure are hard to hit. Maybe your druid was a swarm before they became a person, maybe they speak in a thousand smaller voices or maybe insect come out of his ears. Their mind is quite split, which allows them to do multiple things at once.

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Metamorphosis

You can use your Wild Shape feature to turn into a swarm. You keep your own stats and skill proficiencies and as hit points you gain 4 hitpoints for each level you have in this class. For all other purposes you use the Swarm Wild Shape stat block. At 8th level, you also gain a flying speed of 20ft.

When in Swarm form and you hit a creature with your bite attack, you can use a bonus action to expend a spell slot and deal extra poison damage equal to 1d8 per spell level. Additionally, you learn the Poison Spray cantrip and can cast it while in Swarm form.

These benefits remain for 10 minutes, until you drop to 0 hitpoints (carrying all excess damage over to your humanoid form) or if you drop it voluntarily.

Entymologist

Each time you enter your Swarm form you can choose the type of bugs the swarm consists of, giving additional effects to the creatures you inhabit the same space with:

Butterfly

Charisma based skill checks made against this creature have advantage. The creature has disadvantage on saving throws.

Dragonfly

You can keep a creature in place by hovering around it. In doing so you can us a bonus action to grapple the creature inside your swarm.

Hornet

When you bite the creature makes a Constitution saving throw against your spell save DC or becomes poisoned

Locust

You can change the damage type of your bite and expended spell slots to Necrotic.

Mosquito

When you make a bite attack, you gain half the damage you deal as hit points.

Moth

When the creature moves, you can use your reaction to follow it for 20ft. Additionally, allies have no disadvantage if the creature is invisible.

Colonizing

Your hive can transmit your magic, covering quite some ground. At 6th level, when you cast a spell that has an area of effect you can spend one spell slot higher to gain one of the following benefits:

• Dissipate. Extend the area with 10ft in every direction.
• Delegate. As a reaction you automatically succeed a saving throw to maintain the effect.
• Migrate. As a bonus action you can move the point of origin 10ft in any direction

Hivemind

Your swarm has become so big that you can split it in multiple swarms. At 10th level, you can use an action to can split a swarm in two, each gets half of the hit points the swarm has at that moment. Each swarm gets its own turn, sharing your initiative order, starting next rounf. The new swarm spawns in the same space, has the same entomologist feature and must have at least 20 hitpoints. When only one swarm is reduced to 0 hitpoints the other can remain, so you only revert back when both are dropped to 0. If both die simultaneously your humanoid form only takes the excess damage of one of your choice.

When you gain access to the Beast Shapes feature at 18th level, you can only cast one spell each round, from the location of one swarm. You can still use a bonus action to deal extra poison damage each round. You can only have one form concentrating on a spell.

At 20th level, you can split more often, but each action can only split in half and each split swarm must start with at least 20 hitpoints.

Lord of the Flies

At 14th level, you have mastered your swarm form and can maintain your humanoid form, while also sending out a swarm. As an action you can expend one of your Wild Shape uses to spawn a Swarm Wild Shape in the same space. It functions just like when you would transform fully, but only has 40 hitpoints (so it can split if the player wants). It shares you initiative, starting next turn. When it dies, you take no excess damage. You can only do this once before finishing a long rest and cannot Wild Shape while using this feature.

When you gain access to the Beast Shapes feature at 18th level, you can only cast one spell each round, be it from your humanoid form or a swarm form. You can only have one form concentrating on a spell.