A basilisk is a reptilian creature that has the power to turn creatures to stone. Sometimes this ability is through gazing at them, while other times it is by touch (or both).
The basilisk's actual shape varies depending on the setting; sometimes basilisks are confused with Cockatrices. The most common modern version resembles a large eight-legged lizard; this version appears in both Dungeons and Dragons and Magic: the Gathering. Other games have followed this design.