You can use your action to polymorph into a Small humanoid, into a Small or smaller bird, or back into your true fey form. Your statistics , other than your size and speed, are the same in each form. Any equipment your are wearing or carrying isn't transformed. No matter the form, you always have bright or multi-colored hair, fur, scales, or feathers. You revert to your true form if you die.

You have a special melee weapon attack with your beak. This attack has the finesse property, deals 1d4 piercing damage. It can only be used in your bird form.

You know the minor illusion cantrip, but can only use it to make auditory illusions. You also know the vicious mockery cantrip. When you reach 3rd level you can cast charm person once per long rest. When you reach 5th level you can cast enthrall once per long rest.

When a creature you can see misses you with an attack, you can cast vicious mockery at the attacker.

If three or more flithidirs are within 15 feet of each other, they can use their reactions to start a cacophony. Each creature that starts its turn within 30 feet of one of the flithidirs and that can hear the cacophony must succeed on a DC 10 Constitution saving throw or have disadvantage on its next attack roll or ability check. The DC increases by 1 for each flithidir participating in the cacophony to a maximum of DC 16. To join or maintain an existing cacophony, a flithidir must use its bonus action on its turn and end its turn within 15 feet of another flithidir participating in the cacophony. The cacophony ends when less than three flithidir maintain it. A flithidir can still speak and cast spells with verbal components while participating in a cacophony.

You gain half the normal amount of experience points until you reach 5th level.