The Honeymoon's Over
S3E1
–
Charmed S03E21 · Look Who's Barking
S3E2110th May 200142m7.1(7)
Phoebe has a premonition of a murderous banshee while adding on to the Belthazar section of the Book of Shadows, thus causing her to think Cole is responsible. But when the sisters cast a spell it backfires and turns Prue into a dog, and when Prue gets hit by a car, Phoebe's remorse causes the banshee to attack her, turning her into a banshee.