Harry Potter - Secrets of Hogwarts

This spell blasts away spiders, Acromantulas, or arachnids with a cone of bright scorching light. Each spider-like creature in a 30-foot cone must make a Constitution saving throw. On a failed save, a creature takes 4d6 radiant damage and is knocked back 5 feet plus a number of feet equal to five times your spellcasting ability modifier. On a successful save, it takes half as much damage and isn't knocked back. Any non-arachnid creatures within the area of the spell are unaffected.