Coltrane (Snowball IV) was the Simpson's fourth cat. He was adopted after Snowball III died. His hair is shaped like Bart, same color as Snowball I (which is ironic because the last 2 cats were black and brown), and named after Jazz musician John Coltrane. I believe that Coltrane was the only kitten (baby cat) the Simpsons owned. Like Snowball III, his appearance was short and died in the same episode as Snowball II and III, only that Snowball II appeared in several episodes. Lisa adopted him because she considered his name a sign of good luck. She was so wrong on this feline.
Color: White fur, Green eyes
Age: 4-11 mos (real age unknown, but estimated because he's still a kitten)
First and Last Appearance: "I D'oh-Bot"
In "I D'oh-Bot", he jumped out the window in Lisa's bedroom to his death after being scared by her saxophone (which is ironic because cats are known to land on all fours when they jump. Coltrane probably hadn't learn how to land on all fours yet, since he was a kitten). He was buried next to Snowball III in the Simpson's backyard.