Last week, the Washington Post sports reporter Chelsea Janes noticed a curious development in the Mets’ locker room. First baseman Pete Alonso had carried in a miniature pumpkin and placed it on the top shelf of his locker.

“I have never seen this before,” Ms. Janes wrote on X.

It would not be the last that Mets fans would hear of the pumpkin — the latest in a string of gleefully nonsensical lucky charms that have been embraced by the team amid its raucous run into the playoffs.

This season, Mets iconography has expanded to include Grimace, the purple McDonald’s mascot who now regularly graces the big screen at Citi Field, and “OMG,” a Latin pop anthem recorded by second baseman Jose Iglesias. (A remix featuring the rapper Pitbull is apparently on its way.)

The pumpkin motif — which one headline called the team’s “gourd luck charm” — was arguably born with the same crack of a bat that rescued the team’s postseason hopes.

Last Thursday, Mr. Alonso hit the ninth-inning home run that powered the Mets past the Milwaukee Brewers and into a National League division series. Afterward, he took questions from reporters with his lucky pumpkin in one hand.

“It’s the playoff pumpkin,” Mr. Alonso said, a bottle of Champagne tucked under his other arm.

He gave the pumpkin a little toss, catching it in his palm. He and his wife had procured the pumpkin on a visit to a farm about 20 minutes outside Milwaukee, he said. He had picked it himself.