Medusa

Source: Mythic Odysseys of Theros p. 206

Medusas (often called gorgons on Theros) are closely associated with Pharika, the god of poison and medicine. Pharika has charged her favored servants with guarding secrets of life, health, and immortality that are too powerful to be known by those who lack the wisdom to use them properly. Those who approach a medusa with humility and worthy offerings might receive the creature’s favor. The medusa might propose a dangerous quest to fetch some rare ingredient or legendary relic, promising to reward success with a bit of Pharika’s knowledge. This information might lead to a cure for a plague, an alchemical breakthrough, or a secret of the cosmos.