Draconic Scale Concealment

You have learned to infuse your draconic breath with illusionary magic. Now when you use your Breath Weapon, you become invisible - as if under the effects of the spell Invisibility -  to all targets you hit with it until the end of your next turn. This effect will end early should you attempt an attack or cast a spell before that time.

[Conversion of the Emerald Scale Concealment feat from Dragon 379 of 4e to 5e]