The Chase fans "didn't recognise" Mark Labbett after he shared a snap of himself on social media on Saturday.
The Chaser, also known as The Beast, is currently starring in a pantomime in Northwich. He shared a photo of himself with his secret Santa present, adding: "I suspect [this was] Richard Osman", as the gift was a Pointless board game.
In recent years, Mark has lost a considerable amount of weight, having been 29 stone at his heaviest. And after his recent snap, fans have commented on how different he looks.