How to Unlock The Werewolf
To unlock the Werewolf, you have to kill a ghost. You do this by obtaining the Ghost Gibber, an item which is a starting item for the Scientist, and sometimes drops from the Goodie Machine.
To unlock Werewolf, you need to find a graveyard. If there are ghosts there already, shoot them with your Ghost Gibber. If there aren’t any ghosts there, destroy a few graves and some ghosts should appear. If you destroy the gravestones only ghosts will appear some of the time, so just be wary of that!