The Fellowship of the Basilisk was a group of mainly Slytherin students at Hogwarts School of Witchcraft and Wizardry. The group was founded by Severus Snape, Narcissa Black and Regulus Black, however Severus was looked on as its paramount leader. In addition to the three founders, the group was also joined by Augustus Greengrass, Mary MacDonald, Evan Rosier, Penelope Burke and Jennifer Pratt.