Blenheim was born in 1920. He became an expert on Muggles and authored many books on the subject of them, including Muggles Who Notice, a book published in 1972. The book references the Ilfracombe Incident and the story of "Dodgy" Dirk.
Magical abilities and skills
- Muggle Studies: Stalk was an expert on Muggles and their ways of living, such as how Muggles survive without magic and their use of science and technology, as well as Muggle society and history. He authored many books on the subject of Muggles, including the book Muggles Who Notice, which discusses the rare cases of Muggles who witness magic and the wizarding world, showing he was highly knowledgeable and accomplished in this academic field of wizarding social science.
- 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)