Frederick M. Brown, Getty Images

Sam Simon, a co-creator of The Simpsons, died Sunday (March 8) at the age of 59 after a long battle with colon cancer. TMZ reports that Simon passed away at his home in Los Angeles while surrounded by family. His dog was, reportedly, also by his side when he passed.

Although Simon parted ways with The Simpsons after its fourth season, writer Ken Levine credits him with shaping the iconic series. "I’m here to tell you, the real creative force behind The Simpsons was Sam Simon," Levine told Variety. "The tone, the storytelling, the level of humor — that was all developed on Sam’s watch.”

After being diagnosed with colon cancer in 2012, Simon decided to leave the majority of the $100 million fortune he amassed over the years to different charities he supported. A huge proponent for animal rights, Simon chose to divide his money up to go to various charities that deal largely with abused animals and animal rights, as well as his own Sam Simon Foundation, which helps families who need food in addition to providing veterans with service dogs, as needed.

In a 2014 interview with Maria Shriver, Simon explained his stance on animal rights, saying, "I think that my passion for the animals and against animal abuse is based on the knowledge that these creatures who feel and think can’t speak for themselves and they’re dependent on us for that. And so I feel it’s my responsibility to speak for those that can’t speak for themselves."

He also went on to talk about the support he received from family and friends after discovering his cancer was terminal, "Somehow, I ended up surrounded by people that love me and take care of me and will do anything for me. It’s a good feeling. That’s called happiness.”

The Sam Simon Foundation released a statement about Simon's passing, saying, "For those of us who knew him, his voice will forever echo in our minds; his sense of humor will continue to make us laugh; and his compassion and generosity will continue to impact our lives. Sam, you will be missed by many, but there is a particular sadness among our clinic staff. We have been together for so long, and your absence will forever leave a void in our lives."

Our thoughts go out to Simon's family and friends during this difficult time.