Singer/actress Leann Rimes bursts into laughter whenever she hears festive tune I Want A Hippopotamus For Christmas because she finds the subject matter hilarious.

The Blue star admits she can't help but giggle uncontrollably at the sound of the Christmas song, but it's her favourite during the holidays because it's guaranteed to put a smile on her face.

She tells People magazine, "I heard it years ago and it made me laugh so hard."