Wikipedia
Cheeseface
Cheeseface was the name of the dog who featured on the famous "Death" Issue of the National Lampoon magazine, released January 1973. The cover, photographed by Ronald G. Harris, showed a dog with a gun pointed to his head, and the caption "If You Don't Buy This Magazine, We'll Kill This Dog". The cover was voted #7 in the Top 40 Magazine Covers of the Last 40 Years by the American Society of Magazine Editors.
In early 1976, an unidentified assailant tracked down Cheeseface to the farm where he lived and killed him. How they did this and their reason for doing so also remain unknown.