Sting. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit:2 (1d4) piercing damage. Additionally, if the sunfly is on an Outer Plane, it injects the target with a toxin, the effect of which is determined by the sunfly's location:
Upper Plane. The target sheds bright light in a 5-foot radius until the end of its next turn.
Neutral Plane. If the target is concentrating on a spell or similar effect, it makes the Constitution saving throw with disadvantage to maintain its concentration.
Lower Plane. The target's speed is reduced by 5 feet until the end of its next turn.
Illumination. The sunfly sheds bright light in a 5-foot radius and dim light for an additional 5 feet, or it uses a bonus action to extinguish the light.
Sunflies are whimsical, buzzing inhabitants of the Outer Planes. They travel widely and are important indicators of the health of the realms in which they reside; when sunflies struggle, so do the places they inhabit. Sunflies have stingers that they use to inject natural toxins into other creatures. Planar magic can alter a sunfly's toxin so that its effect is different depending on which Outer Plane the sunfly is on.