Book 1 in the DinosaurUs series.

When the clock strikes midnight, Spookasaurus arms herself with her spookbag, brimming with terrifying inventions and sets off to put the spooks up the locals. 

Naturally, being so fantastically frightening, everything goes just as she expected, or at least it was going as expected, until she tries to spook a dinosaur unlike any she's spooked before...