You have no idea where the sarcophagus came from, but you know enough about enchantments to know there must be

You have no idea where the sarcophagus came from, but you know enough about enchantments to know there must be an easy way to open it. Experimenting with the engravings in various combinations, you discover when you press your finger against the skull symbol with your hand on the lid, the cover slides aside easily. Your triumph is short-lived, however — as the lid slides open, there is the sound of something... something huge... stirring within the sarcophagus. You hear a rattling whistle like air pushed through a leaky bellows and scraps of flesh fly from the sarcophagus... whatever's inside is huge, angry, and far from dead.