Celebrity Parents Arnold Schwarzenegger Jokes About Powerful 'Gene Pool' Behind Daughter Katherine's Baby on the Way Arnold Schwarzenegger opens up about becoming a granddad for the first time — and why there's "a lot of power" surrounding daughter Katherine's pregnancy By Jen Juneau Jen Juneau Twitter Jen Juneau is a digital news writer for PEOPLE. A '90s teen and horror film connoisseur, she started at the brand in 2016, after a decade of working as a technical writer and then moonlighting as a journalist beginning in 2013. Originally from New Orleans, Jen grew up both in NOLA and Florida and eventually attended the University of Central Florida in Orlando (still her home base!), where she earned a bachelor's in English/technical communication, with a minor in magazine journalism. People Editorial Guidelines Published on May 19, 2020 12:00 PM Share Tweet Pin Email Arnold Schwarzenegger can't wait to be a grandfather! The actor and former California governor, 72, chatted with Jimmy Fallon via video call for Monday's at-home episode of The Tonight Show, where he opened up for the first time about daughter Katherine Schwarzenegger expecting her first child with husband Chris Pratt. "Can you believe that? That is really exciting news that Katherine now [is] pregnant and [is going to] have a baby — I don't know when exactly, but sometime this summer," Arnold said. "And inevitably, I'm really looking forward to playing around with whatever it is, she or he, and [having] some fun." He also noted that the pregnancy is "unique" as far as their combined family "gene pool" is concerned: "There's three gene pools here. You can do Kennedy, Schwarzenegger and Pratt." "I mean, we can do anything. We can go and solve the Cuban Missile Crisis, we can go and kill Predators with our bare hands and we [train] dinosaurs," Arnold joked. "Think about it. That is a lot of power here." Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. Arnold Schwarzenegger (L); Katherine Schwarzenegger and Chris Pratt. Katherine Schwarzenegger's Mom Tells Chris Pratt He's Going to "Have Another Beautiful Family Member" But the "worst thing," quipped the Austrian-born star, "is if this kid ends up, you know, with my accent. I mean, that's what we don't want." Arnold — who's a dad of five children, including Katherine, 30, and Patrick Schwarzenegger — says "the trick of" fatherhood is simply communication. PEOPLE confirmed Katherine and Pratt's baby news last month. The couple wed on June 8 of last year during an intimate ceremony in Montecito, California. The baby on the way will be The Gift of Forgiveness author's first child while Pratt, 40, is already dad to 7½-year-old son Jack, whom the actor shares with ex-wife Anna Faris. VALERIE MACON/AFP/Getty RELATED VIDEO: Chris Pratt Won Over Father-in-Law Arnold Schwarzenegger in the Gym: "He's a Strong Guy" Speaking with Extra in January, Arnold said that while he was excited for his newlywed daughter and her husband to have children, the decision on a timeline was in their hands. "I don't push it because I know it's going to happen eventually. It's up to Chris and her when they want to do that," said the Terminator actor and former bodybuilder. "I'm looking forward it to, yes." A source previously told PEOPLE that the Guardians of the Galaxy star was initially attracted to his wife's strong spirituality and bond with her family. "They're very compatible and have a lot in common," said the insider. "Family is very important to both of them, as well as their spirituality."