Editor's note: We've done our best to edit out all of the expletives, but some viewers may still find the embedded video offensive.
Was it a sea turtle? A baby whale? A tuna? A giant flounder?
Nope, just a sunfish, but Michael Bergin of Malden, Massachusetts, didn't know that when he and his friend Jason Foster first spotted it.
According to the Boston Globe, the pair were out in Boston Harbor on Foster's boat last week when they spotted the giant sea creature. Bergin captured the entire ordeal on video, narrating in an expletive-filled rant in a thick Boston accent as his friend Foster attempted to reel it in.
"I don't know what this, but Jay says it's a (expletive) big sea turtle," Bergin says in the video. He then quickly corrects himself, saying, "It's a baby (expletive) whale, man!"
Bergin posted the videos to his Facebook page, and they've gone viral, with hundreds of thousands of views.
No word yet on what happened to the sunfish.