Cops got a scaly surprise when they responded to a report of a burglary at a Staten Island home.

Soon after walking into the back door of the Mariners Harbor home on Bush Avenue at about 7 p.m. on Tuesday evening, police found an alligator in a bathtub.

ESU officers then responded and rescued the gator, handing it over to Animal Care Centers.

No one was home at the time, police said, and no charges had been filed on Wednesday.

Alligators are one of a long list of animals that are illegal to keep as pets in the city.