Fly

You or the creature you touch gains Fly, which gives them controlled Flight, Hover and their movement speed is doubled while flying until the end of the encounter. If they take damage while flying higher than 5ft above the ground, their altitude drops by 20ft. If this would reduce their altitude to the point where they touch the ground, they become rooted and cannot fly again until the end of their next turn. If the attack that reduced your HP came from an flying creature other than yourself, you do not lose altitude.