Curse of the Crummy Mummy! - Joe McGee - Bog

"The Junior Monster Scouts are going to host an exchange scout, a mummy staying at Castle Dracula for the summer. But when their guest's pet sphinx gets loose, it starts causing trouble by turning people who can't answer its riddles to stone! Can the scouts and the mummy capture the sphinx, answer its riddles, and convince it to turn everyone back to normal?"--