fans are in for some fun cameo surprises when season 5 drops later this year, and while Peyton List can't divulge about exactly who joins in on the fun in the upcoming season, she says it was so impressive it freaked out the cast!The 23-year-old actress spoke to ET's Cassie DiLaura and they got on the topic of celeb cameos after discussing Carrie Underwood's surprise appearance during season 4. The Grammy-wining singer appeared in «The Fall» episode and sang «The Moment of Truth,» which was originally performed by Survivor on the soundtrack to the original 1984 film, .List said she was on set the day Underwood filmed her scene, and it was quite a sight.«They were having me train for the tournament scenes and I was just trying to learn all of the karate,» List explained, «but I got to go in and see her and she had her tour bus there and all of her people there.