Burger King has pulled off the juiciest April Fools’ Day joke yet.

The flame-broiled hamburger chain lured a bunch of carnivorous customers into eating a vegetarian version of their Whopper sandwich — using buzzy alternative beef purveyors Impossible Burger.

“If it’s not beef I don’t want it,” says one unsuspecting customer to the camera.

But “little did they know,” the voice-over says, “their Whopper patty was actually made from plants.”

In tandem with the stunt, the fast-food chain also announced the Impossible Whopper would be available at 59 Burger King restaurants in the St. Louis, Missouri, area, where they’ll be testing the concept.

The eerily beef-like plant-based patty was remarkably well-received by the duped customers.

“This is a f–king cow,” says one customer in “udder” disbelief.

Adds another, “I’m confused. I’m re-evaluating my life.”

Impossible Foods recently released an update to their “burger” formulation called Impossible Burger 2.0. — to rave reviews. It’s primarily made of water, soy protein, coconut oil, sunflower oil and leghemoglobin, also called “heme” — the source of the patty’s meaty flavor.

For those of us not in the St. Louis area, Impossible Burger 2.0 can also be found at select Bareburger (including the Yankee Stadium franchise), Applebee’s, Red Robin, White Castle and five Napkin Burger locations.