Parnassius is a genus of northern circumpolar and montane butterflies usually known as Apollos or snow Apollos. They can vary in colour and form significantly based on their altitude. They also exhibit altitudinal melananism, a high-altitude adaptation. They have dark bodies and darker coloring at the base of their wings, which allows them to absorb solar energy more quickly.

Butterflies are winged insects from the lepidopteran suborder Rhopalocera, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The group comprises the superfamilies Hedyloidea and Papilionoidea. The oldest butterfly fossils have been dated to the Paleocene, about 56 million years ago, though they likely originated in the Late Cretaceous, about 101 million years ago.