Zac Efron, Krysten Ritter
Credit: NPG; Courtesy of Zac Efron/WhoSay

When a fan Tweeted Zac Efron during an online question-and-answer session to ask if he had any pets, the The Lucky One actor replied with this holiday shot of his Australian Shepard, Puppy. Meanwhile, The B— in Apartment 23's Krysten Ritter carried her petite pooch, Mikey, while running errands in Los Angeles. See more stars and their furry friends in the gallery.