The clues: In the White Tiger's video montage, they makes multiple references to their "giant career," but mention how when they think about singing, they become "a big scaredy cat." It's pretty obvious that this person isn't a professional singer, so based on their height and stature alone, many believe the White Tiger is either a football player or wrestler. In the video, there is an award that reads: "Ultimate Championship For Clam Shucking: 51 clams" which could be a reference to the New England Patriots, while the White Tiger's quote about how they are "ready to get in the ring and smash the competition" could be a clear sign that they're a professional wrestler.
Who it might be: While the judges offered up John Cena and Rob Gronkowski's names, it's also likely that Dwayne "The Rock" Johnson could be under the mask given the clues.