Terrifying video released by the NYPD Tuesday shows a wild-eyed straphanger shouting and threatening to cut passengers with a box-cutter while spitting on the floor of a subway car.

“I will cut you so bad you mother won’t even recognize you,” the goon shouted aboard a Manhattan-bound C train in Brooklyn around noon Saturday, according to police.

The would-be slasher continued to shout racial slurs at passengers from his seat — and then got off the train at the Kingston-Throop Avenues station in Bedford-Stuyvesant.

There have been no arrests, police said.