While on "The Hills," Holly Montag proved to be a protective sister and a loving daughter, but now she's got a new role to try on for size: mother.

Montag, who announced she was expecting a baby with husband Richie Wilson late last year, has officially given birth to a boy, according to Us Weekly. And you won't soon forget his name: Isaiah Hawk Wilson. Welp, there's gonna be no confusing him during his eventual classroom roll call!

And while baby Isaiah is surely a beautiful bundle of joy, Holly's pregnancy wasn't so sweet and even knocked the formerly baby-crazed Heidi Montag, Holly's sister, off the fast track to motherhood.

"I was like, 'I think I can put [pregnancy] off for a little bit because you look really uncomfortable!'" Heidi told Us Weekly in March in reference to Holly's prenatal pains.

Can you believe Holly is a mom? Share your thoughts on the recent addition to "The Hills" family, look back at Holly's most memorable moments on the show, and be sure to send along your congratulations!