MOUNT KISCO, N.Y. (AP) – Officials are trying to figure out who dropped off a three-foot-long alligator in front of the Westchester County water department.

A sign on the wooden crate containing the green alligator warned: “Do not open. Live Gator.”

At first, workers weren’t sure that it was alive because it was so still. But then it stirred.

Ed Sordellini, a machine and equipment operator said, “We tapped the crate a little and it hissed and we all jumped back.”

The workers figure it was a Halloween prank and have reached out to wildlife experts.