On this week's episode of 'Mask King', a former member of I.O.I appeared on the show and wowed everyone with her performances.

The member came out with a masking 'Blue Shrimp' to collaborate with 'Blowfish Lady' for the first round. Together, they sang Lyn's "Back In Time". The two harmonized well and showed off their pure vocals that grasped the hearts of the audience immediately. Unfortunately, 'Blue Shrimp' was not able to get past the 'Blowfish Lady' to move onto the next round and her identity was revealed.

However, before the mask was taken off, the two singers faced off in a freestyle dance battle. 'Blue Shrimp' danced to Kara's "Mister" which resulted in a guess of Seungyeon which was incorrect.

When the mask was taken off, the audience and the panel were surprised to find none other than Kim Chung Ha singing Lee Hyori's "10 Minutes" effortlessly. 

Check out all the performances below and above!

SEE ALSO: Chung Ha and Etham team up for new song 'Find Love'