Bill Moody, who was better known by his performing name of Paul Bearer, passed away on March 5 at the age of 58, according to TMZ.
He reportedly suffered a blood clot three days before his death and had been suffering from respiratory difficulty.
Paul made his World Wrestling Foundation debut in 1990 as a funeral director character who managed several key wrestlers, including The Undertaker.
"WWE is saddened to learn of the passing of William Moody, aka Paul Bearer," the WWE said in a statement. "Moody made his WWE debut in 1991 as the manager of The Undertaker and went on to become a memorable part of WWE over the course of the next 20 years."
"Our deepest condolences go out to Moody's family, friends and fans," the statement continues.