Wolf

The Wolf is Rolf's sworn enemy. "Wolf" is not his real name but it is what Rolf calls him since he wears a wolf mask

History
When Rolf was young and still in the Old Country, his father's flock of sheep was haunted by the Wolf. The Wolf appears to be a man with a wolf mask with a muscular build. Why he wanted the sheep has not been said but it is possible that he wanted to eat them (what else do wolves do).

In the end, Rolf fought back against the Wolf with an unknown outcome. Rolf later thought that Ed was in an alliance with Wolf since Ed kept receiving wolf items from an unknown penpal.

Weither or not Wolf is still at large is unknown but Rolf's warning lead to believe he is.

Trivia

 * Wolf is the only Adult to make a physical apperance in the show.
 * Wolf is thought to be a werewolf by some fans
 * Wolf might have actually been Ed's penpal as Gerda was not Ed's penpal.