Jack Riley, a long time actor known for his role on “Rugrats,” died Friday. He was 80 years old.

Ginger Lawrence, the wife of Riley, confirmed his death to Deadline on Friday. Riley died of pneumonia and infection in Los Angeles.

Riley voiced the character Stu Pickles from 1991 to 2005 on the classic animated Nickelodeon series. Stu was the lovable — yet kooky — father of Tommy and Dil Pickles. The character was known for creating bizarre inventions that usually ended up breaking or going wrong. Despite his failures, Stu never gave up on trying to create something new — even though his wife, Didi, and brother, Drew, encouraged him to move onto other ventures.

Riley also voiced the character in “The Rugrats Movie,” “Rugrats in Paris: The Movie,” “Rugrats Go Wild” and the spinoff series, “All Grown Up,” which aired on Nickelodeon from 2003 to 2007.

Tara Strong, who voiced his on-screen son Dil Pickles on “Rugrats,” took to Twitter to comment on his death.

Prior to lending his voice to “Rugrats,” Riley appeared on “The Bob Newhart Show” from 1972 to 1978. Over the years he also landed guest roles on TV shows like “The Love Boat,” “Diff’rent Strokes,” “St. Elsewhere,” “Night Court,” “Family Matters,” “Married with Children,” “Friends,” “The Drew Carey Show,” “Seinfeld,” and fellow Nickelodeon series “The Secret Life of Alex Mack.”

Watch some of the most memorable Stu Pickles moments below, including Stu making chocolate pudding and Stu sleepwalking: