The character is portrayed as a large, belligerent, dim-witted bully who obtains what he wants by intimidating others into doing his work for him, or by cheating. He and his family members are shown to misuse idioms in ways that make them appear foolish and comical, despite their intention to insult or intimidate. He frequently calls others "butthead".

In 1955, Biff coveted Lorraine Baines who did not return the sentiments. In the original 1985, Biff's marital status is unknown as no mention of a wife was ever made in the trilogy.

The alternate 1985 reveals that Lorraine, widowed after the murder of George McFly, ended up marrying Biff in 1973 so that her children could live a better life. In a video clip after their wedding, Biff is asked, “how does it feel?”, to which he replies, “Third time's the charm.”

By 2015, Biff has a teenage grandson, Griff, suggesting that Biff had at least one child by 1985. The animated series reveals that Biff has a son, Biff Jr.

The character is named for studio executive Ned Tanen following an incident years earlier where Tanen reacted aggressively to a script being pitched by the film's writers Bob Gale and Robert Zemeckis. Tanen accused the two of attempting to produce an antisemitic work with their 1978 film, I Wanna Hold Your Hand. Drafts of Back to the Future show the character with the middle initial of "H", but this detail was omitted in further revisions.