Joe Costa-Silva said he didn't know what was coming after him until it emerged out of the lake near his home in Boca Raton.
After it got out of the water, it started running after him. That's when Costa took out his mobile phone recorded the incident on video.
Wildlife experts said the aggressive behavior could be an otter mom protecting her pups or it could be a sign of rabies.
Another man said an otter came after him while he was riding his bike.
