A new video, fittingly titled "Happy Anniversary, All I Want For Christmas Is You!," features Katy Perry, Ariana Grande , Ali Wong, Millie Bobby Brown, a "nice" Kim Kardashian alongside "naughty" Kris Jenner, and ugly sweater aficionado Ryan Reynolds doing their best impression of the elusive chanteuse. Props to Laverne Cox for bringing her own wind machine. And how cute is Olivia Newton-John with her little sign showing how hopelessly devoted to Mimi she is? But what's with Carey's new bestie Billy Eichner using his phone? Does he not know these words by heart by now? Come on!