Anyone with a mullet saved $5 on the price of admission Monday, and there were prizes given out as well.
There's something memorable about the mullet.
"Hairstyles come in and out, but I don't think that one is going to come back in anytime soon. Although there was that one kid, I forget his name, on 'American Idol.' He had that mullet, the red-haired kid," Kristina Tooley said.
Jaromir Jagr sported it to stardom with the Pittsburgh Penguins, and some still call it the hockey helmet.
Yet these days, the hair-do of the 80s has become a hair-don't.
KDKA's Rick Dayton asked zoo patron Mike Swick about the perception that the mullet is redneck.
"I say it's not because to have a red neck, it has to be exposed to the sun. There's no exposure here," Swick explained.
These days, a close-cropped style is the preferred choice. Sure, some thumb their nose at the trend and rock the mohawk instead.
Conservationists from the zoo are doing their part to keep the mullet from going extinct.
The mullet has many nicknames, including "the achy-breaky big mistakey" and "the Camaro crash helmet," among others.
People who wear them say it's more than a hairstyle, it's a way of life and that's why the zoo wants to make sure it never goes extinct.
"The mullet is rapidly becoming an endangered species and as a conservation organization we feel not just an obligation, but a moral imperative to herd, protect and cultivate Pittsburgh's finest mullets," Swick said.
Stylistically, most think the mullet stinks like fish that shares the name, but there are some who defend it still.
The winner of the zoo's contest for best mullet gets a behind-the-scene zoo tour. Others will win zoo bucks and a chance for a free haircut.
"I don't know, but I might have to, what, cage myself or protest to save the endangered species," Joe Scalise said.
For those who love what the mullet represents, getting it cut will never happen because as we all know, the mullet is business in front and a party in the back.