I'd never heard of Packer, but he's been the subject of several pop-culture treatments. It's mentioned in a conversation in Dashiell Hammett's The Thin Man. There are a couple of songs about him. One is a humorous song from Phil Ochs -"The Ballad of Alferd Packer"- which tells the tale:
"That county had 6 Democrats until he did arrive. Well only one lives on today; he ate the other 5."
C.W. McCall wrote "Comin' Back for More" about Packer:
"It was Al Packer's legendary, coronary, fast-food cannibal bar and buffet."