Surf's Up!: An Acorn Book (Moby Shinobi and Toby, Too! #1)

In rhyming text, Moby Shinobi and his dog Toby head to the beach for a day of fun, where Moby tries to put his ninja skill to work helping his friends build a sandcastle which unfortunately cannot withstand the weight of even a small ninja--however when a sailboat springs a leak, it is Moby Shinobi to the rescue.