Arnold Thompson (b.1983) was a wizard who studied at the Hogwarts School of Witchcraft and Wizardry from 1994 to 2001 and was sorted to Slytherin house. After graduation he moved to the United States where he began working in a department of the local Ministry of Magic.
After school, Arnold at one somepoint started a romantic relationship with his former classmate Mafalda Prewett and so they got married and moved to the United States. Christmas holidays in 2017, Arnold and his wife received a visit from Mafalda's family. According to Isaac Prewett, Arnold has a nasty taste in choosing Quidditch and just hope for the worst team in America. He also twists for the Manhattan Fallen, a Quodpot team.