So me being the silly person I am, rather than doing something productive, I came up with this one night when I was bored. I was reading an article the other day about how by 2050, the world's oceans will have more plastic in them than fish. That's where the inspiration for this guy came from.
He's made of rubber, created by the ocean itself with the materials that humans deposited into the sea as waste. He leads a simple life, thinking of only a few things each day. One of those is to seek out swimmers, capture them either via hypnosis or through use of rubber tendrils that dwell inside him that he can extend and use to grasp prey.
He's two-faced. Although it'd be easy for him to snare a swimmer with hypnosis, he usually opts to lure them out away from their companions using playful tactics, be they other swimmers, scuba divers, beachgoers, or fishermen. Once he's had his fun, in and away they go.
He doesn't require food to live, so his victims aren't digested. They're dragged off to his lair where they're either put to work, kept as toys, or well; let's just say one dolphin alone wouldn't be enough to clean up the ocean.