Pennsylvania Sen. John Fetterman revealed a startling new look Saturday that had some social media users likening him to Walter White, the infamous meth-cooking chemistry teacher played by Bryan Cranston on AMC’s “Breaking Bad.”

“Lost a bet with Karl,” Fetterman posted on X, formerly known as Twitter, with a selfie showing off a blocky pair of eyeglasses, a bushy new mustache — and the disappearance of his signature gray goatee.

The freshman Democrat, 53, did not describe the wager he had made with his 13-year-old son, but the photo sparked hundreds of reactions.

“Breaking sad,” one critic snarked.

“ITS TIME TO COOK,” posted Eric Torres.

Another revised Fetterman’s portrait to add the caption “Am I the knocks who one?” — a mixed-up version of the beloved character’s “I am the one who knocks” catchphrase, meant to mock the senator’s verbal stumbles in the wake of his 2022 stroke.

But others seemed to approve.

“Got a bit of Walter White there, useful for negotiations,” wrote Charles Mathewes, a professor at the University of Virginia.

The former Pennsylvania lieutenant governor was left with hearing and other cognitive issues after suffering a stroke in May of last year, just before the Keystone State’s Democratic Senate primary — then concealed the extent of his disability from voters.

A June poll found that 50% of Pennsylvania voters disapprove of Fetterman’s job performance, while just 39% approve.