Two years ago, a Johns Hopkins University study published in The Lancet estimated the number of civilian casualties in Iraq. It came up with a number—100,000 dead—that was higher than any other estimate at the time and was mostly ignored.

Some of the scariest stories happen when fluffy, innocent creatures turn murderously evil. Producer Alex Blumberg tells one such story, about a raccoon gone bad.

Host Ira Glass talks with producer Alex Blumberg and his parents about a bad dog they once had, and how nothing—not getting hit by cars, attacked by bigger dogs, or being shipped off to live on a farm—could stop this dog from coming home. "The Cat Came Back" is sung by Nedelle Torrisi.