Snowball III was the Simpson's third cat. Lisa adopted him after Snowball II died after passing a persian, a tabby, a siamese, a skunk, and a cat with an eye infection. Snowball III had heart worms from the song Lisa sang as she was preparing his food for the first time. His appearance didn't last too long, unlike Snowball II. He died in the same episode.
Color: Brown fur, Light Green eyes
Age: 16-19 (real age unknown, but estimated by the shape of his body)
First and Last Appearance: "I D'oh-Bot"
In "I D'oh-Bot", he drowned trying to catch the fish in their fish tank while Lisa was preparing his food for the first time in the same episode (which is ironic because cats know how to catch fish. Snowball III must have slipped on the top and didn't know how to swim, so he drowned).