I was walking on a high bank along the Yangtze River, which was an enormously wide delta full of islands large and small. I was with someone, but I don't recall who. I see people swimming down in the river and I comment on how foolish that is-- besides the industial pollutants in the water, god knows how many parasites and diseases there are. My companion says there are even more immediate dangers than those: there are the "analodes", which are apparently dog-like predators that have migrated down here from Russia. They look like amphibious Afghan hounds, with tremendously strong jaws. He points down and sure enough, there are a couple of the beasts entering the water to get some of the swimmers.
But the swimmers have a dog of their own, a big black great dane, and it chases the analodes away-- pursues one all the way to shore before catching it in its teeth by the neck and snapping it with a shake right below us.