While the singers usually perform in group rounds, a wildcard contestant will go up against them each week. If the new competitor does better than the others in the group, then they get to stick around.
Thus far, most of the rogue singers have shown off tremendous talent, and one may have what it takes to win the entire season.
One of these gifted performers is the Yeti, who only made his Wildcard debut in the April 14 episode. After just two performances, viewers think they've figured out who is under the mask.
Keep reading for the Yeti's clues, and for the popular guesses about his identity.
The Yeti had a "mammoth" clue package.
During the new contestant's introduction on the April 14 episode, many references were made to suggest that the Yeti comes from a family of strong women. In his clue package, the Yeti hinted that he came from a tough place, but that he was able to succeed thanks to the females in his life.
"As a Yeti, I only come out of hiding for a mammoth reason. And here, it's to be a loud force to be reckoned with. So, watch your step," the singer began. "Where I come from, too many yetis become monsters. But, I had a secret weapon: a village of warrior women, who were always there to show me the way. Having them as motivators and teachers was golden, and made me the abominable gentleman I am today."
The Wildcard performer then said that he's on the series to show his appreciation for those who supported him.
"Knowing these warriors had my back gave me the confidence to go for the mountaintop when others wouldn't even dare. Yetis are usually chased from the village, but I was raised by it. Being here is a 'thank you' to them," he continued. "And you know they saved the best Wildcard for the last."
Throughout the clue set, the Yeti was seen in a snowy climate. He carried a pile of wood to a house before he went inside. Bunnies were featured around the home, and the Yeti was served toast with jam and berries. There was other food around him as well, including eggs, and three cupcakes.
A red heart made out of paper was also shown, and a kiss was blown to the Yeti before the video ended.
An ice box was later used to collect the judges' first guesses.
In Episode 7, we learned even more about who could be behind the Yeti mask. We saw a ring toss as the Yeti shared, "I had a once in a lifetime role that created an avalanche of success, but my ego caused tons of chaos," which suggests a scandal.
Then we saw the Yeti holding cutouts of the letters A, B, C, and D, and then a little puppy stuffed animal. Then he line danced with two other guys wearing "Happy New Year" hats.
Who is the Yeti on 'The Masked Singer?' Fans have a few guesses so far.
When Yeti performed "If It Isn't Love" by New Edition on the April 14 episode, his distinct voice had many convinced that R&B singer Omarion is underneath the mask.
The various clues from the initial Yeti introduction video also point toward Omarion. The singer's full name is Omarion Ishmael Grandberry, which explains why the Yeti was eating toast with berries on top.
The red heart (love) and the bunny (hop) statues might be a reference to Omarion's stint on the Love & Hip Hop: Hollywood reality series. His mom, Leslie Burrell, also appeared on the first season of the show. She was a key confidante to him.
Omarion has celebrated Leslie on social media in the past, and he's thanked her for being a "super mom." He also has three sisters, so he definitely grew up surrounded by women.
The pile of wood that the Yeti was carrying could be a nod to Inglewood, the city he was born and raised in.
The dog could represent Omarion's many collaborations with Bow Wow, and the ABCD could be rearranged to represent his time as a judge on 'America's Best Dance Crew.'
Finally, one of Omarion's most popular songs to date is "Ice Box," which explains why the judges submitted their guesses in one.
Though Omarion has been a popular guess for Yeti, he's not the only one fans are buzzing about. Some are convinced that Ray J is actually the Yeti. He also appeared on Love & Hip Hop: Hollywood, which would, once again, explain the bunny and the heart.
The reference to strong women in the clue package could be about Ray J's older sister, Brandy, and her influence on his life and career.
Others now think Yeti could be an Oscar-nominated actor, since he references "the role of a lifetime."
The Yeti's identity will only be confirmed when he's unmasked. Since he's already shown his musical abilities, it could be quite a while before viewers see that.
The Masked Singer airs on Wednesdays at 8 p.m. ET on Fox.