The Princess in Black, Books 1-3: The Princess in Black; The Princess in Black and the Perfect Princess Party; The Princess in Black and the Hungry Bunny Horde (Unabridged‪)‬

The Princess in Black: Princess Magnolia is having hot chocolate and scones with Duchess Wigtower when . . . Brring! Brring! The monster alarm! Stopping monsters is no job for prim and perfect Princess Magnolia. But luckily Princess Magnolia has a secret: she’s also the Princess in Black! Can Princess Magnolia sneak away, transform into her alter ego, and defeat the monster before the nosy duchess discovers her secret?
 
The Perfect Princess Party: Today is Princess Magnolia’s birthday party, but just as her guests are arriving . . . The monster alarm! Princess Magnolia runs to the broom closet and becomes the Princess in Black! She rushes to the goat pasture, defeats the monster, and returns to the castle before her guests discover her secret. But every time Princess Magnolia is about to open her presents, the monster alarm rings again. Don’t those monsters understand that now is not a good time for an attack?
 
The Hungry Bunny Horde: Princess Magnolia and her unicorn, Frimplepants, are on their way to have brunch with Princess Sneezewort. But just when they arrive, Princess Magnolia’s monster alarm rings. Princess Magnolia and Frimplepants transform into the Princess in Black and her faithful pony, Blacky. But when they get to the goat pasture, all they can see is a field full of darling little bunnies nibbling on grass, wiggling their fluffy tails. Where are the monsters? Are these bunnies as innocent as they appear?