Okay, it's not YA, but this is a friend's book so I just had to share. You can pre-order it now at Amazon or B & N.
Blurb- Ten-year-olds Ben Silverstein and Pearl Petal have had quite a busy summer in the typically quiet town of Buttonville. Ever since Dr. Woo opened her doors, things have been more exciting than the senior center on pudding day! Together, Ben and Pearl have encountered all sorts of magical beasts -- from a sasquatch, to a lake monster, to a leprechaun, to a dragon, to a unicorn.
In "The Griffin's Riddle," when Ben and Pearl discover that Dr. Woo and the sasquatch are both sick with Troll Tonsillitis, the two must travel to the Imaginary World in search of the only cure -- a griffin's feather. But can they convince the "King of Creatures" to surrender one? And at what cost?
Suzanne Selfors delivers a wild journey filled with mythical creatures and zany adventures that are anything "but" imaginary.