Erik Cowie was found dead in New York City on Friday US time, according to multiple outlets.
NYPD told E! News about the incident without confirming the man's identity: "Upon arrival, police discovered a 52-year-old male unconscious in the bedroom of the location. EMS was on scene and pronounced the male deceased."
TMZ reports there was nothing suspicious surrounding his death, and initial reports suggest his death was likely from "natural causes" but the cause of death is yet to be determined.
Cowie stayed to look after Joe Exotic's animals after Exotic went to jail.
"It comes with great sadness to say that a dear friend and hard working employee has passed away," The Greater Wynnewood Exotic Animal Park said in a tribute on its Facebook page.
"He absolutely loved all the animals and would show up early to check on each and everyone. He had his Demons but the animals helped bring joy and happiness in his life," the tribute continued.
Cowie normally resided in Oklahoma according to the Daily Mail, and previously worked as Joe Exotic's head zookeeper.
Since the reality show aired on Netflix, Cowie made headlines for his comments against Exotic, E! News reports.
"I knew cats were being shot," he told reporters in 2019. He testified against Exotic, who faced allegations of animal abuse.
"Cage space. We needed three cages. He wiped out five cats," he alleged of his former boss.
"He came up [with] a 4-10 in his hand and I knew he just shot Cuddles. I heard it, and he comes up the hill and goes...Erik. If I knew it was going to be this easy to just walk right up the cage, I was just going to kill them all."
According to the New York Post, he was arrested for a DUI in Oklahoma earlier this year.
