Static-Ridden Fleece

Wondrous item, uncommon

This clump of soft fleece feels numbing and electrical to the touch. When you cast a spell that uses fleece as a material component that isn't consumed in the casting (such as major image, minor illusion, phantasmal force, or silent image), you can choose to use this fleece to enhance the spell. The fleece must be on your person. When a spell is cast in this way, choose one of the following benefits:

• A creature that uses an action to interact and come into physical contact with the spell must first make a DC 13 Constitution saving throw. On a failed save, the creature ceases trying to interact with the spell (potentially delaying it recognizing the spell as an illusion) and can't make opportunity attacks until the start of its next turn.

• When the spell ends, you can choose for it to release a small blast of electricity. Each creature within 10 feet of the spell when it ends in this way must make a DC 13 Constitution saving throw. On a failed save, a creature takes 1d10 lightning damage and is stunned until the start of its next turn. On a successful save, a creature takes half as much damage and isn't stunned.

Each time the fleece is used, roll a d4. On a 1, the fleece loses its electrical charge and becomes nonmagical.

The stormslope alpaca is unique, capable of attracting and harnessing the innate magic in high mountain storms, suppressing all but the light from lightning and producing illusory flocks to confound predators. For those native to the same storms, the threat is only in choosing wrong, in wasting energy chasing phantoms. For those wandering from elsewhere, the shock is not merely surprise, but pulling the lightning back out from the light.
For those seeking to borrow this power, there are herdsmen who keep the alpacas for their wondrous fleece. It requires a keen eye, resilience to shocks, and the patience to put up with the beasts' trickster disposition.
Even once the fleece has lost the storm's power, these herdsmen still swear by its comfort.
— Excerpt from An Accounting of Enchanted Beasts