Do you see much of your uncle, Marcus?"
"Not... not much of him, no,"
"Well, of course, I daresay he's busy ... I doubt he invented the Wolfsbane Potion without considerable hard work!"
"I suppose... Er... he and my dad don't get on very well, you see, so I don't really know much about..."
-- Horace Slughorn and Marcus Belby (HBP7)
A “thin and nervous-looking” boy, in Ravenclaw and a year ahead of Harry. A candidate for the Slug Club because his Uncle Damocles invented Wolfsbane potion (HBP7), but not a favored member because he does not see much of his Uncle Damocles.