Potty

From UnknowableWiki

Potty is an insult frequently used to provoke Harry Potter. Draco Malfoy refers to him as "Potty" when he, Crabbe and Goyle meet Harry and Ron aboard the Hogwarts Express on September 1, 1993 (PA5).

Draco also uses the nickname while bragging about the newly-formed Inquisitorial Squad to the Trio and Ernie Macmillan (OP28).

Pansy Parkinson taunts Harry with this nickname, trying to frighten him about an upcoming match (Ron's first as a member of the Gryffindor Quidditch team). Harry is unperturbed, and responds with a jibe (OP19).

Peeves calls Harry "Potty" when they meet in a hallway right after Harry is kicked out of Dolores Umbridge's first Defence Against the Dark Arts lesson (OP12). When Harry asks Luna to go to a Slug Club party with him, as friends, Peeves overhears the conversation and flies around the castle, announcing, "Potty loves Loony!" (HBP15).

Peeves also refers to Harry as "Potty" when he sees Dobby and Kreacher fighting in the hospital wing after Harry summons Kreacher (HBP19).