Three of the most famous old school horror movie actors are together in this classic.

The Wolf Man
(1941)

Larry Talbot (Lon Chaney) returns to his home in Wales to live with his father John Talbot (Claude Rains).  Larry buys a walking stick with a silver werewolf emblem.  When a girl is attacked by a beast, Larry beats the beast to death with is walking stick.  A gypsy fortune teller informs Larry that the beast was her son (Bela Lugosi), a werewolf.  Since it bit him, Larry will now become a werewolf.  Under the full moon, Larry turns into a werewolf, and kills a villager.  When he returns to human form, Larry is haunted by shadowy memories of his actions as a wolf.

As the wolf man, Larry attacks Gwen.  Larry's father beats the beast to death with the same walking stick.  To the father's horror, the dead beast turns back into Larry.  

Thanks Joseph C!