Shadow Zone (novels)

Shadow Zone is a series of 13 children's horror fiction books written in the 1990s by several authors using the pen name J. R. Black. 
Each book is a different story, with new characters. A child or a few children meet a monster who asks for help and usually threatens them or their family. Aggressive at the beginning, they may finally be nice or touching. The books use black humor.
Two of the books, "The Undead Express" and "My Teacher Ate My Homework", have been made into films.
Similarity to "Goosebumps".
This series is similar in style and tone to the very popular "Goosebumps" series. Other children's horror series from the 1990s include "Bone Chillers", "Shivers" and "Graveyard School".