Their little girl, whose name has not yet been revealed, was adorably dressed as the Incredible Hulk, with a green knit hat and matching shirt. The baby's superstar parents decided to keep her face a mystery by covering it with an animated image of the Hulk.
"My first Halloween," reads a sticker on the post.
Malik and Hadid revealed the birth of their daughter in late September and later shared black-and-white photos of the baby grasping the crooner's fingers with her tiny hand.
"Our baby girl is here, healthy and beautiful," Malik tweeted at the time. "To try put into words how i am feeling right now would be an impossible task. The love I feel for this tiny human is beyond my understanding. Grateful to know her, proud to call her mine, and thankful for the life we will have together x."
Hadid was first linked to the singer in late 2015, and later starred in the steamy music video for his debut solo single "Pillowtalk." While the couple's relationship has been on-and-off over the last half decade, Hadid publicly confirmed her pregnancy in April during an interview on The Tonight Show Starring Jimmy Fallon.