Yet subsequent movies mentioned the nicknames Wormtail and Padfoot. A lot of things in the films must have been confusing to people who didn’t read the books. Another weird thing I’ve noticed is that in the fourth movie, Barty Crouch Jr steals from Snape to make polyjuice potion and he blames Harry. But those who only watched the movies and didn’t read the books wouldn’t have known that Harry and his friends stole from Snape to make polyjuice potion before.