Warning: be on the lookout for Daggohead.
According to Finn, Daggohead is a fish that kills the world. He hates humans, and he hates sharks. And he hates glass. And he hates flowers. Other things he hates: underwater snakes, rattlesnakes, the sun, thunder and lightning.
Things he doesn't hate: numbers, walls, curtains, wood, crabs, dogs, chairs, bags, clothes, movies, newspapers, pillows.