Credit: Courtesy Taylor Swift

The family that wears onesies together . . . Taylor Swift got overtaken by the spirit of the season on Christmas Eve, and shared her excitement with fans on her Instagram, naturally. The "I Knew You Were Trouble" singer, 24, shared an adorable family snapshot on Instagram, in which she and cute brother Austin, 21, wear matching red plaid onesies as they grin in front of what appears to be a surprisingly humble family Christmas tree.

"Matching Christmas onesies is a thing that's happening right now," the Grammy winner captioned the photo.

Taylor wore a brown fuzzy hat with ears, while her bro wore a Santa hat. The Nashville resident has been sharing her holiday cheer throughout December -- making Christmas crafts and cookies with BFF Hailee Steinfeld, and posting a Throwback snapshot of her younger self in 1993.

Austin recently shared an old Christmas present from his famous sister -- a needlepoint rendering of a quote attributed to Gary Busey, "When Angels Fly Inside Your Heart, That's When You Can Fly." He is a junior at Notre Dame.

Swift topped's 2013 list of the "Top 20 Celebs Gone Good" for the second year in a row. One Direction came in second, Beyonce in third and late actor Paul Walker in fourth this year.