Need a new series for your 3rd-5th Grader? Geronimo Stilton to the Rescue

We've recently discovered the wonderful world of Geronimo Stilton.  Always on the look out for a good long series (having exhausted Casa de Arbol and Capitan Calzoncillos), the Geronimo Stilton series of books (up to 33 with more coming out next year) is a funny, punny, fast paced set of chapter books with great illustrations and playful typography. 
The Spanish is accessible and the vocabulary is rich but not obscure so kids will be able to easily figure out the words within the context of the sentence.  There's a little bit of of the vosotros  (-ais/-eis) but not enough to be inpenetrable. 

Who is Geronimo Stilton?

Geronimo Stilton is the international bestselling author of the Geronimo Stilton chapter book series --- and he's a mouse! His United States publishing company, Scholastic, calls him a VIR (Very Important Rodent) and hails him as a big cheese.