A mermaid?
This guy is obviously delighted at the huge fish he’s caught. The trouble is, he must have forgotten to bring a tape measure to prove just how big the fish was. No matter. He just asked his girlfriend for help. She must be very obliging because no sooner did he ask. She must have flipped onto her hands (flippers?) and made like a mermaid. And he’s really pleased because his fish is officially nearly as tall as his own personal mermaid. The perfect catch.