When Jenisse Heredia, a hair stylist, first heard the sound of breaking glass at her Long Island salon on Saturday afternoon, she thought a car had struck the building.

But when she looked up from working on a client’s hair, she saw something even stranger: A massive deer was sliding across the floor toward her.

“It was huge,” said Ms. Heredia, who owns the salon. “I was freaking out.”

The animal leapt through the front display window of the Be.you.tiful hair salon in Lake Ronkonkoma at around 12:20 p.m., breaking the glass pane and injuring one woman, according to the police.

After scrambling across the slippery floor, the buck threw his antlers into the air a few times and ran into the break room at the back of the salon, Ms. Heredia said.