According to the Oxford English Dictionary and Merriam-Webster dictionary, the term derives from 'do as in hairdo.
Takahashi and Mike Mignola, the creator of Hellboy, also participated in an art exchange (with Takahashi drawing Hellboy with Yugi Mutou's hairdo, a Millennium Puzzle, and a duel disk and Mignola drawing Hellboy wearing a Millennium Puzzle and a Yugi T-shirt).
He started drawing for the company in 1993, drawing a revival of Peter Piper From The Dandy, revived from The Magic Comic, but looking nothing like Watkins' creation, instead sporting an elvis-like hairdo and purple Jumper.
De Wilde's habit of not attending to hair care after removing his helmet and it being severely tussled as a result led to his moniker of "Afro Bob", a reference to the "Afro" style of "hairdo" that was popular with people of African descent, particularly during the 1970s (it has made something of a comeback in recent years).
Sinead's makeover during the cycle was a fuzzy buzz-cut haircut inspired by Natalie Portman's hairdo in V for Vendetta.
Bouffant hairstyles, popular at the time, were sometimes made with "hair-rats", which were pads of old hair taken from brushes stuffed into the hairdo to create volume.