This is a short video of a labrador who paddles out into the shallows to play with another dog swimming there, then realizes it isn't a dog, and quickly returns to solid ground to stare at the mysterious beast from a safer distance. I imagine that dog telling its friends when it got home, "I don't know what it was, but it wasn't one of us -- it didn't have legs and was way too good a swimmer." Obviously, that one dumber friend will ask if was a mermaid, and this dog will tell it of course it wasn't, I know what the hell a mermaid look like, Dewey. Full disclosure: Dewey also buries ice cubes in the yard.
Keep going for the video.
Thanks to Cyndi M, who agrees making new friends is hard.