Dirty Potter/WMG

The assembly from Hell is a Secret Test of Character.
The final prize for surviving Pooh's onslaught is going to bed with Jim Dale. Pooh gives them advance warning at the end of chapter 1, but when the 40 days and 40 nights initiates, the hordes were preparing to upend the Hundred Acre Wood. Everyone was going to die from the start, but only Tigger was able to reject it, and thus his courage was rewarded with a night with Jim Dale.

Winnie the Pooh killed David Benedictus.
Why else would he hold out his head?

Jim Dale is Fuckbeak.
Jim Dale describes Fuckbeak as the "sickest of sick fucks". So is Jim Dale. He knows an awful lot of details about the nonstop Hogwarts orgies, which we know Fuckbeak secretly watches (and jerks off to) from the bushes outside. And he somehow knows all about Fuckbeak's disgusting behavior at Hogwarts, which the faculty went to great lengths to keep secret.