Fans of Courage the Cowardly Dog are expressing their sadness and condolences online following reports that voiceover artist, Thea White, has passed away. According to White's brother, John Zitzner, in a public Facebook post, the actress died on Saturday morning during surgery in Cleveland. He also included a video of White sending love to her family and talking about her planned recovery that was filmed prior to the surgery. She was 81 years old.

"My sister recorded this prior to her surgery. She fought. She left us today at 11:05," Zitzner wrote on the post.

"If you can, prayers for my sister Thea... surgery at Cleveland Clinic tomorrow morning to remove tumor in liver! Thanks!!," Zitzner said in a separate post on July 19.

A separate statement posted to Facebook by Brad Zitzner expands upon White's battle with cancer and the pain that's now being felt by the family. You can read the full statement below.

"Sadly we lost our legendary Feefer (the voice of Muriel) on Friday morning after she fought hard with courage to try to beat her liver cancer and to resume life or to die trying. (She ended up with an infection after cutting out the damn cancer) It was Friday morning during the round of Chaz' tournament that she lost the battle. Carrying those clubs was just so hard but we got through the round - you got to see his best round ever."
Feefer was the greatest cheerleader to me and my family. We just arrived back to Ohio to get home to Jackson and the pain is so deep. Thanks Feefer for your leadership of your family. The roll you have taken with my kids and all your family sadly can't be replaced. I can see hundreds of fan tributes already online so your love was shared far and wide.
I've never met a person who knew you who didn't think you were the greatest person alive. That lasted even up through your stay in the hospital as I'm told the nurses and doctors also fell in love. You loved life and even know I know the final outcome I love your decision to go for it and to try to win. Damnit sticks!"

Thea Ruth Zitzner was born on June 16th, 1940, in Newark, New Jersey. After graduation, she studied acting at the Royal Academy of Dramatic Arts and the American Theater Wing, working as an actress in theaters and on Broadway. At one point, she served as the personal assistant for Marlene Dietrich. In 1983, she married drummer, Andy White, who filled in for Ringo Starr on drums for the Beatles' first single "Love Me Do." He died in 2015 at the age of 85.

White had stepped away from acting following her marriage to White and worked as a librarian in Livingston, New Jersey for many years. She returned to acting when she was offered the voice role of Muriel Bagge on the animated series, Courage the Cowardly Dog. She voiced Muriel for all four seasons of the popular series between 1999-2002 and reprised the role for the video game, Cartoon Network Racing, in 2006 and the animated short The Fog of Courage in 2014.

Prior to her passing, White had delivered one last performance as Muriel Bagge for the upcoming animated crossover, Straight Outta Nowhere: Scooby-Doo! Meets Courage the Cowardly Dog. It will serve as her final acting role. Muriel's husband, Eustace, will be voiced by Jeff Bergman in the movie as original voice actors Lionel Wilson and Arthur Anderson have since passed away. Marty Grabstein will return as the voice of Courage. A trailer for this crossover has been previously released.

With the news of her passing going viral, thousands of fans are paying tribute on Twitter. One popular tweet reads: "I just received some very devastating news. Thea White, best known by many as the phenomenal longtime voice of Muriel from Courage the Cowardly Dog, has passed away at the age of 81. She was such a sweet and lovely lady animated and IRL and she will be dearly missed."

Echoing countless others, another fan writes, "thank you for lending your voice to one of the most iconic cartoon characters of our generation. you perfectly captured and conveyed muriel's gentle character through your voice acting. rip, thea white."

At this time, our condolences go out to the family and friends of White. It's clear from the reactions from fans on social media just how loved she is and she will be forever missed. Rest in peace. This news comes to us from John Zitzner on Facebook.