They probably saw it in a movie while in Hollywood.
In the anime, yes.
In the games, yes. In Ranger: Guardian Signs, barnacles can be seen underwater. But that's the only one. Although I really don't consider that. We've yet to see real-world cats, dogs, birds, fishes etc...
It's interesting how this thread shifted from "Pokemon's death", to "Existence of Real Animals"...
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I think the world of Pokemon is a lot darker than it is portrayed to be, so yeah, Pokemon kill each other, etc.