Police are on the hunt for a puny perv who appears to be lurking on the Upper East Side.

A man who stands 4 feet, 11 inches tall and weighs only 120 pounds is wanted for groping up to seven different women in the past six months, police said.

His most recent victim was a 29-year-old woman, who he allegedly attacked Saturday as she entered her apartment building at 5:30 a.m.

The suspect grabbed her and threw her to the ground, reaching under her dress to touch her before fleeing, according to police.

Police say the suspect often approaches women from behind.

Since Jan. 5, the man has been targeting women between the ages of 25 and 31, police said. He singles them out in the late evening and early morning hours, reaches under their dresses and fondles them.

On Saturday, June 11, the suspect approached a woman walking up the stairs, lifted her skirt and spanked her, police said.

The serial groper is said to be a Hispanic man between 25 and 30 years old and has black hair.

Police are offering a $2,000 reward for information that leads to his arrest.