Hogwarts Whomping Willow

The Whomping Willow is a violent tree situated in the Hogwarts grounds over a secret tunnel that leads to the Shrieking Shack in Hogsmeade. There is a special knot on the trunk of the tree that when pressed "freezes" the tree from its violent thrashing, allowing one to pass into the tunnel.

The Whomping Willow was planted the year that Remus Lupin &mdash; a werewolf &mdash; started school at Hogwarts, to cover the entrance to tunnel to the Shrieking Shack, enabling Lupin to transform in a safe place, away from other humans.

The tree attacked Harry Potter and Ron Weasley in 1992 when they crashed a Flying Ford Anglia into its branches.

In the third year, it also destoyed Harry's Nimbus 2000 broomstick.