From this story on AOL News:
Call it the jellyfish version of "Jaws." As many as 150 people were stung by a 40- to 50-pound jellyfish at a state park in southern New Hampshire this week. And the jellyfish, identified as a lion's mane jellyfish, was not even alive. Officials said the incident at Wallis Sands State Beach in Rye, started when a lifeguard spotted the jellyfish about 100 yards from shore and dragged it in with a pitchfork. The jellyfish broke up en route.
Then, people in the water started having painful reactions. Those stung by stingers on the huge dead creature included children, vacationers, and others attending recreation programs at the beach, reports New Hampshire's WMUR 9. "My daughter was screaming," Shannon Kirshenbaum tells the TV station, of her two-year-old. "We were trying to figure out what was wrong with her, so we picked her up and started to get out of the water, and that's when they announced that they had caught a jellyfish that had split into pieces and that there might be tentacles in the water."