In the beginning, the bunnies were simply young women who worked as waitstaff in Playboy's clubs.
From 1960 to 1986, the brand ran 40 nightclubs, according to Atlas Obscura, as well as some intermittent casinos in England and the Bahamas. Prospective bunnies had to audition in order to get the job.
It's unlikely that any of Hefner's girlfriends — or Playboy Club bunnies, for that matter — stand to inherit anything. The mogul's own third wife will "looked after" and nothing more, thanks to an "iron-clad" pre-nup, according to the Mirror.
Hefner died at the age of 91 Wednesday. The Playboy Mansion, where the modern-day bunnies lived, will now go to Daren Metropoulos, who bought it for $100 million last year.
Today, the term "bunnies" is often used to describe Hefner's girlfriends, as well as Playboy Club employees. The Playboy founder's life with his girlfriends has been depicted on reality TV shows like "The Girls Next Door."
A new Playboy Club is set to open in New York City sometime this year.
While Hefner claimed to be a proponent of sexual liberation, Steinem's reporting shone a light on some of the objectification and problematic working conditions bunnies experienced.
In 1963, journalist Gloria Steinem went undercover as a bunny to write an exposé.
In a Metro article, one former bunny reported that in the 1980s, bunnies had to be at work an hour early to dress and do their own makeup. The extra time was never paid.
At the same time, workers could lose merits and wages for mistakes like messy lockers, lateness, and failing to maintain a fluffy, pristine cottontail.
Bunnies could earn extra cash by collecting merits for working private parties, taking extra shifts, or helping management out.
The job required bunnies to walk and stand around in high heels for hours. The manual offered all sorts of tips on dealing with the pain, including encouraging bunnies to roll their feet "over an empty Coke bottle."
Lipstick shades should be "vivid" to avoid a "washed out" look, wigs were encouraged, hosiery was to be refrigerated after use, hands had to be manicured, and jewelry — aside from Playboy cufflinks — was strictly banned.
Costumes were to be worn "proudly and prettily."
Unsurprisingly, some of the manual's strictest — and strangest — instructions pertained to appearances.
The manual advised bunnies to address all male Playboy Club employees "in a cheerful, cooperative manner."
A "bunny mother" — which one Playboy Club's 1968 manual describes as a role "similar to that of a college advisor" — would be in charge of supervising the bunnies.
There was also a ban on drinking alcoholic beverages and gum chewing on the job.
Bunnies working at Playboy Clubs had to abide by some strict rules. They could be immediately fired for dating other employees or guests.
The name comes from an unexpected source. As a University of Illinois student, Hefner would sometimes dine at Bunny's Tavern in Urbana, Illinois. Apparently, the name stuck with him.