The Menace

Karloff Mennis (commonly referred by his nickname, The Menace) is a fictional character that made his primary debut at the end of the Goosebumps HorrorLand book, Escape From HorrorLand. He is the owner of Panic Park and was the primary antagonist in The Streets of Panic Park. He has a second face which The Menace got after travelling through a 2-way mirror.

Biography
The Menace performed extreme experiments on making scary rides which resulted in a variety of accidents including a rollercoaster that fell off it's track and crashed into some parked cars. The Menace claimed to have turned the riders brains into mush with the wind though it turned out he had been lying to prevent the kids from returning to Horrorland.

All of the villians throughout the series exept Monster Blood, Mrs. Hardesty, and the evil camera began to collaborate under The Menace to try and get revenge on the kids. In The Streets of Panic Park, The Menace tried to get the kids fear level up to 100 on the Fear Meter.

If The Menace were to achieve that goal than Panic Park would return to reality. The Menace's plan was to never let the villians or the children escape if he were to return Panic Park to reality. In the end the villians formed an unlikely alliance with the children to stop The Menace from achieving this goal.

They did this by making the children's fear level return to normal by making them laugh. As it turns out Panic Park was shrinking as the children's fear meter reduced and the Menace then informed the children that if Panic Park were to reduce so far to the point of disappearing, everybody would disappear along with it.

The kids ended up going on the Whirlwind to take the path back to Horrorland. Once they came back they met up with their parents and returned home, almost as if nothing had ever happened.

Trivia

 * His first name is a reference to horror star Boris Karloff, who is famous for his roles as the Monster from Frankenstein and Imhotep from The Mummy.h