A Long Island family made a jaw-dropping discovery Saturday when they found a baby alligator trying to beat the heat in their backyard pool.

Bayport resident Joe Baron says he went out to check the pool filter around 7:30 p.m. when he stumbled on the lizard as it was lounging in the water.

“I see a stick, and I look at the stick, and I’m like, ‘It’s attached to legs — and a head!’ I’m like, ‘Oh my god, that’s an alligator!’ ” Baron told The Post on Sunday. “At this point, I’m just stunned. A frog you get once in a blue moon, but an alligator, not in a million years.

“Then he jumps from the filter and starts swimming all around the pool!”

Baron’s daughter thought her dad was pranking her at first.

“She’s like: ‘We’re on Long Island — there’s no alligator in the pool,’” Baron recalled.

But seeing was believing, and the 10-inch-long reptile then set off a flurry of activity as Baron’s kids tried to corral the little beast using a pool skimmer.

“He would spin around, and the kids would flinch — nobody wanted to touch him,” Baron said.

They eventually netted the creature and deposited it into an old fish tank, where it was chilling out Sunday.

“The kids are coming up with all different names: Chomp Chomp, Titan, Rex — they couldn’t decide, That was a big conversation last night,” Baron said, adding “Now we gotta call somebody and say, ‘Take him.’”

While alligators are not native to New York, it’s not the first time that one has surfaced on Long Island. More than a dozen — assumed to be illegal pets who outgrew their welcome — were captured over a nine-month period in 2012 and 2013. And a 6-footer was seized from a Suffolk County home in 2016, according to CBS New York.

Baron plans to see if his brother-in-law, who works at the Center for Science Teaching and Learning in Rockville Centre, will take the gator off his hands.

“It’s totally unexpected, but it’s fun,” he said of the gator excitement.