Light Grenade
From KGB Wiki
Otherwise known as a potion of dumbass, this devious concoction releases light compacted within in a powerful burst when there is a significant temperature change on its surface receptors. These are usually triggered when a captive is asked for any potions they have by their captor, but are given this instead.
History
The light grenade was developed in the laboratories of Camelot as a weapon against the invading forces of Mordor. Need we say more for you to understand its aweseomeness?