Choi Hyeon-seo (; born October 15, 2000), better known by his stage name Hiss (), is a South Korean beatboxer and producer. Hiss is perhaps best known as runner-up in the Grand Beatbox Battle 2017 and winner in the Asia Beatbox Championship 2019. He is currently a member of the group Beatpella House. Hiss made his debut with released single "Jumpin" on October 18, 2018.