Katherine Schwarzenegger honors father Arnold on 75th birthday

July 31 (UPI) -- Author and animal rights advocate Katherine Schwarzenegger paid tribute to her father, film icon Arnold Schwarzenegger, on Instagram this weekend.

"Happy birthday daddy!! We love you so much! You're the best and most fun opa and dad and we are all so lucky to have you in our lives! Happy happy!!" Katherine captioned a gallery of photos of her as a child with her father.

Her husband, actor Chris Pratt, posted his own message on the social media platform.

"Happy birthday to the man, the myth, and the legend. Love you @schwarzenegger!" Pratt wrote, alongside a photo of him and his father-in-law smoking cigars.

Arnold is known for his movie roles in The Terminator franchise, True Lies, Twins, Kindergarton Cop and The Expendables, as well as for serving as governor of California from 2003 to 2011.

He was married to broadcast journalist Maria Shriver 1986 to 2021. They share four adult children together, but are now divorced.

Arnold also has an adult son from an extramarital affair.