Taylor Swift and Zac Efron
Credit: Lester Cohen/WireImage

Taylor Swift and Zac Efron celebrated the premiere of Dr. Suess' The Lorax in Los Angeles this weekend, as the pair lent their voices to a set of characters in the animated film. "That movie is filled with adorable-ness," Swift Tweeted after the premiere, where she walked an orange carpet in honor of the tangerine fictional character. "So lucky to have gotten to be a part of it." See more celebrities at this weekend's hottest parties in the gallery!