United Kingdom, May 25 -- Rory Culkin has become a dad.

The 36-year-old actor and his girlfriend, cinematographer Kate Arizmendi, welcomed a baby girl named Havoc Moon into the world on May 24, and she announced the news the following day on her Instagram Stories.

Kate posted an adorable shot of their bundle of joy sleeping with the caption: "Her in the womb while I'm screaming System of a Down. We're so in love with you."

In a second story, Kate uploaded a photo of her and Rory's daughter looking wide-eyed down the camera, with the caption: "15 mins after pushing her out and so alert and excited about life already.

"Also hello girl baby Rory."

And in a third story, Kate posted a shot of Rory cradling Havoc whilst sitting in a chair,...