Playboy mogul Hugh Hefner had a soft spot for bunnies.

Hefner died at his home in Los Angeles, California, Sept. 27, at the age of 91.

Not only did Hefner adore blonde bunnies of the human kind, but also endangered bunnies found only in the lower Florida Keys.

The endangered Lower Keys marsh rabbit – the world’s smallest subspecies of marsh rabbit officially known as Sylvilagus palustris hefneri – is named after Hefner.

“The subspecies name, hefneri, is in recognition of generous research funding from Hugh Hefner, the creator of the Playboy Bunny,” states the website of National Key Deer Refuge on Big Pine Key.

That bunny, weighing up to only 3 pounds, was listed as federally endangered on June 21, 1990, because of habitat loss and death by vehicles and free-roaming cats, according to the U.S. Fish & Wildlife Service.

Only about 100 to 300 of the rabbits exist, with a probability of extinction within 50 years, the FWS states. Officials say it’s “too early,” post-Hurricane Irma, to provide current population estimates.

The creatures live around Big Pine Key, Boca Chica — home to Naval Air Station Key West — and on smaller backcountry islands.

In 2007 U.S. wildlife officials caused a stir when they revealed a plan to trap feral cats as a way to save the tiny bunny.

Hefner donated funds to Stand Up for Animals Inc., a Keys animal control provider overseeing shelters in Marathon and Big Pine Key.

His donation drew publicity to the rabbits’ plight and helped to halt trapping of the free-range cats.

The provider named a rescue tomcat ‘Hef’ and kittens after Hefner’s girlfriends Bridget, Holly and Kendra on the TV show, “The Girls Next Door.”

Hefner once explained why he chose a bunny as his icon, describing it as “a fresh animal, shy, vivacious, jumping — sexy.”

Hefner’s death may mean the extinction of a famous lifestyle. In the Keys, his namesake bunny also faces extinction.