A man who sneaked up behind a Central Park jogger, threw her to the ground and dragged her off the path last month in an alleged attempt to rape her says it was all a joke and "her eyes" made him think she had a sense of humor and would find it funny.

Saul Alvarez was arrested about half an hour after the assault the night of June 28 and pleaded not guilty to first-degree attempted rape at his arraignment in Manhattan Supreme Court Thursday.

Shortly after he was taken into custody, the 21-year-old suspect told investigators "her eyes made me think that she had a good sense of humor and she would be a good person to play the prank on," according to court papers.

He told authorities he jogged behind her for a few minutes, then made his move when a potential witness on a bike rode away. He said he hooked his right arm under her arm from behind, and "took her down to the ground." Once he grabbed her, the woman began screaming, managed to break free, ran off and called police.

"When I first took her down, I said 'prank," he told cops. "I've never done this prank in my life. This is the first time ever."

"My prank was supposed to be to scare her by grabbing her from behind and taking her down to the ground," Alvarez said.

He later clarified: "The only other time that I ever played this prank was on my wife few years ago and that's how we met."

The self-professed prankster says his other favorite jokes are to switch out skateboard wheels with marshmallows and replace people's coffee with water.

"I always 'Gotcha,'" he said.

Alvarez faces up to 15 years in jail if convicted. Information on an attorney for him wasn't immediately available.