Daniel Gerson, who co-wrote Disney/Pixar’s “Monsters, Inc.” movies and “Big Hero 6,” died at his home on Saturday. He was 49.

According to a family statement, Gerson had been battling brain cancer.

The screenwriter frequently collaborated with Robert L. Baird. Together the duo co-wrote “Monsters, Inc.” and its prequel, “Monsters University,” as well as “Big Hero 6,” which won the Oscar last year for animated feature. Gerson was also the voice of maintenance monsters Needleman and Smitty in “Monsters, Inc.” and Desk Sergeant Sergeant in “Big Hero 6.”

Gerson and Baird have been credited with assistance on Pixar’s “Inside Out” and “Up,” as well as “Chicken Little.”

Born in New York, Gerson attended Cornell University, where he majored in English, and later obtained an MFA from the graduate film school at NYU. After graduation, he moved to Los Angeles to begin his writing career, getting his start as a staff writer on the NBC comedy “Something So Right.” He later transitioned to animated films for Disney/Pixar, where his films grossed over $2 billion worldwide.

He is survived by his wife, two children and parents.

Donations in Gerson’s memory can be made here at UCLA’s Brain Tumor Program.