We'll bite your tail, Geronimo! / Geronimo Stilton ; illustrations by Giuseppe Facciotto (pencils), Carolina Livio (inks), and Valeria Cairoli and Paolo Vicenzi (color) ; translated by Lidia Morson Tramontozzi.
When Professor Greenfur changes color from green to orange, the spacemice travel to his home planet of Photosyntheson to investigate and find that his relatives are all being threatened by tiny aliens with sharp teeth.
