For some reason, perhaps cost savings, Looney Tunes made many cartoons in color in the late 1930s and into the 40s and many which were black & white. Most of the black & white ones, especially the later ones, were Porky Pig outings but for some reason they decided to make "The Haunted Mouse" without color even though the pig is no where to be seen. Perhaps it's because it is about ghosts and they thought this would enhance the look of the short.
A hungry cat wanders into a ghost town...where he is annoyed by a ghost mouse. In many ways, the cartoon is like a Tweety or Bugs Bunny cartoon, as the hero (in this case a dead mouse) annoys the aggressor for our amusement. However, I found the cat a bit more sympathetic...especially since you really cannot defeat a ghost unless you arrange for an exorcism...or if you do what they did at the end of this cartoon! Overall, very dark...but funny and worth seeing.