Something scary is happening in Goosebumps Horrorland, the all-new, all-terrifying series by R.

L. Stine. Just how scary? You'll never know unless you crack open this classic prequel!

Evan visits an eerie old toy store and buys a dusty can of Monster Blood.

But then he notices something weird about the slimy green ooze.

It keeps growing. And growing. And growing.