Ratooey

From the Super Mario Wiki

Lumpy, a green colored Ratooey.

The Ratooey are a rare species of rat that have only appeared in Paper Mario: The Thousand-Year Door. In fact, Ratooeys are so rare, there are only two specifically named Ratooeys in existence: Lumpy and the Businessman. Other Ratooeys exist; however, they don't have specific names.

Apparently, Ratooeys come in a multitude of colors; however, green and blue are their only confirmed fur colors. Additionally, Ratooeys are very tall compared to other species. Ratooeys achieve this height by standing upright on their hind legs.

The species may be based on, or even related to, the Mukumuku species, as they both share very similar characteristics.