Monster Blood 

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. And all that growing has given the Monster Blood a monstrous appetite. . . .