Michael Dahl 
Ooze Control [PDF ebook] 

After school, a boy boards an odd-looking bus. Inside, the floor, the seats and even the ceiling are covered with chewed-up wads of gum. Soon, the sticky wads grow thicker, climb higher, come alive . . . and the bus windows will not open! Can the boy escape before the ooze takes control? Step aboard the addictively creepy SCHOOL BUS OF HORRORS, where the final destination is never expected.