Swarm Escape

When you, or are the space you are in, are targeted by an attack you can see or subject to any spell or hazard that would require you to make a Dexterity saving throw you may use your reaction to cast this spell. You immediately transform into a chosen swarm, as detailed below, and can move as indicated below away from danger. This movement does not provoke any attacks of opportunity. If you move out of the space targeted by the attack, spell or hazard you are safe from it, essentially allowing you to nullify the danger. You then return to your normal form. Once this spell has been cast you cannot cast any other spells greater than a cantrip until the end of your next turn. The transformation follows the rules of the Polymorph spell except you retain your hit points, hit dice, and class features.

The swarm form you choose will have different benefits:

Swarm of Bats - you move double the speed of the swarm and the next attack against you before the start of your next turn by a creature that witnessed the effect of this spell is made with disadvantage.

Swarm of Rats - you move double the speed of the swarm and any time before, during or after this movement you can make a Stealth check with advantage, and you apply your own proficiency bonus if you have proficiency, even if you do not have cover or are within line of sight - normal hiding rules apply when you reform.

Swarm of Ravens - you move the speed of the swarm and you have advantage on the next attack you make before the end of your next turn.