Radcliffe Joins The 'Slug Club,' Talks Hogwarts' Potion Master

Daniel Radcliffe as Harry PotterIs he a buffoon? A mastermind? Remorseful or just out to save his own neck? It's been more than two years since "Harry Potter and the Half-Blood Prince," but hard-core fans are still debating the motivations of Horace Slughorn, the brand-new potions master at Hogwarts School of Witchcraft and Wizardry.

Don't worry, so is Harry Potter himself.

"Most of the time he's gonna be very funny," star Daniel Radcliffe told MTV News of Slughorn's portrayal in the upcoming movie adaptation. "But then you will really see the dark side of him."

The dark side, of course, is displayed most prominently in what's sure to be a vital part of the film – Slughorn's memory of giving young Tom Riddle information on creating horcruxes. Harry is ultimately able to retrieve the memory in a moment of great sadness, when he pleads with a sobbing Horace to erase the damage he's done and honor Lily Potter. It's moments like these, said Radcliffe, that make "the tragedy [of Slughorn] outweigh the comedy."

But while Radcliffe was happy to dish on Slughorn the character, the 18-year-old megastar became tight-lipped when we asked him who would play the slippery Slytherin. (Boy, do we sometimes wish we had a healthy stock of Veritaserum).

"I don't know if I can say," Radcliffe sighed. "I don't know if it's been announced, and I don't want to spoil any of our surprises."

What do you make of Slughorn? Let us know below and then swing by our own casting list and let us know who you think should play him.