Biff

Biff, according to Peter Salus (A Quarter Century of UNIX):

• Was the dog belonging to Heidi Stettner, a graduate student in Evans Hall at Berkeley
• Would often accompany Heidi to her classes and her office
• Was very friendly and would enjoy fetching balls the students would throw down the corridors
• Had his picture on the bulletin board with the graduate students, with the accompanying legend indicating he was working on his Ph.Dog.
• Was the nomenclature origin of the asynchronous mail notification package biff(1) appearing in 4.0BSD, written by John Federero, another grad student at Berkeley. John, along with Bill Joy, spent much time coming up with an explanation for biff, and came up with "Be notified if mail arrives" (although I've also heard feebdaed once tell me that it can mean "Bark if From found").
• Once got a B in a compiler class.
• Did not bark at the mailman. Heidi indicated this to be a "scurrilous canard."
• Died in August 1993, at the age of 15, according to Salus and both the FreeBSD and OpenBSD manpages.

According to Melinda Shore in this Usenet article, Biff actually owned Heidi Stettner, although by that point he was 13 years old and one leg was mostly gone.

According to Steven Sargent in this Usenet article, Biff's full name was Bifford Studworth III. He would ride the Evans Hall elevators and would attend database seminars.

I don't know how important Biff is to Unix history, but I thought he was cool. =)