The actress and her actor-director husband, Daniel Gillies, welcomed their second child on Saturday, April 4, in Los Angeles.
Born at 5 a.m., son Theodore Vigo Sullivan Gillies weighed in at 8 lbs., 14 oz., and measured 20.5 inches. He joins big sister Charlotte Easton, 18 months.
“Welcome to the party, Little Buddy. We love you so much,” Cook, 35, Tweeted Wednesday.
The couple announced the pregnancy in January. “We’re as happy as we were surprised by this wonderful news! We haven’t slept since 2013 and welcome advice from all parents who survived Two Under Two,” they joked in a statement.
The Originals star Gillies, 39, and Cook, whose TNT show Perception aired its final episode in March, were married in 2004.