Mister Jingles

The Green Mile #2 The story continues with the addition of two new characters, one a new death row inmate--William "Wild Bill" Wharton. The other, a mouse, called Steamboat Willy by the guards who first noticed him and later Mr. Jingles by Eduard Delacroix, one of the death row inmates who takes in the mouse and makes him his pet. ([source][1])

[1]: www.stephenking.com/library/novel/green_mile_the_mouse_on_the_mile_the.html