The boy, whose name was not reported, was reported missing from his home at about 3:45 p.m. Saturday, The Philadelphia Inquirer reported. Police K-9 units picked up his scent about 90 minutes later and tracked him to the creek.
East Greenwich Police Chief Barry Jenkins said the boy was found in water up to his neck about 400 yards offshore.
"They saw him sinking in the mud and heard him screaming," Jenkins said, adding that the tide was quickly rising.
"They got under his armpits and pulled him from the muck," Jenkins said.
East Greenwich Officer Bill Crothers became stuck in the mud during the rescue operation. Another officer was able to pull him out and get him to safety.
The boy was reunited with his father and taken to a hospital for an evaluation.