Harry, Ron, and Hermione start back to the castle from Hagrid’s cabin. Crookshanks chases Scabbers, and a big black dog drags Ron into a tunnel under the Whomping Willow. Crookshanks stops the tree from attacking Harry and Hermione, and they follow the cat down the tunnel to emerge in the Shrieking Shack outside Hogsmeade. They find Ron a captive of Black, who disarms them (PA17).
Animals that turn out to be surprisingly human, pursuing one down a hole in the ground and through a passage, and then seeing a tiny rat transform into a full-sized person are all reminiscent of Alice's Adventures in Wonderland by Lewis Carroll. -BB