Queen of Christmas Mariah Carey really is the gift that keeps on giving.

Mariah Carey, bringing her Merry Christmas One & All! Tour to town, was joined by Ariana Grande and Jennifer Hudson at Madison Square Garden, where the pop trio debuted a festive live collab of "Oh Santa!

Ariana Grande surprised fans and joined Mariah Carey and Jennifer Hudson on stage at Madison Square Garden for a festive performance of the song, Oh Santa!

Mariah Carey enlisted help from her friends, Ariana Grande and Jennifer Hudson, to create holiday magic for fans. On Saturday, Dec. 9, the "All I Want for Christmas Is You" singer surprised concert-goers at her Merry Christmas One And All!

Mariah Carey had a very special Christmas surprise! On Saturday, during the New York City stop of her Merry Christmas One and All Tour, the self-proclaimed Queen of Christmas was joined by Ariana Grande and Jennifer Hudson in Madison Square Garden.