Blenheim was born in 1920. He became an expert on Muggles and authored many books, including Muggles Who Notice, a book published in 1972. The book references the Ilfracombe Incident and the story of "Dodgy" Dirk.
By the 1990s, he was featured on a famous Wizard Card and was featured wearing a golden pocket watch.
He was awarded a recognition in a Chocolate Frog Card Collection.
- Harry Potter and the Philosopher's Stone (video game) (Appears on a Famous Wizard Card)
- Harry Potter and the Chamber of Secrets (video game) (Appears on a Famous Wizard Card)
- Fantastic Beasts and Where to Find Them (Mentioned only)