The black cat jealously eyed up the mother otter, who seemed to be unfazed by its gaze as she swam along the River Don near Aberdeen.
The unlikely scene was captured by amateur local photographer Colin Black, 47, who lives near the river.
He said: “I heard a rustling in the bushes below the path and then looked down to see a black cat perched right on the riverbank.
“I could see it was interested in something, but I did a double-take when an otter appeared right next to it swimming by with a fish in its mouth.
“The cat seemed pretty frustrated that it couldn't just jump in and grab the fish, so it was pretty funny to watch it eyeing up the otter.
“It's always great to see wildlife when I'm out photographing, even better when you witness some natural behaviour, but when you see two completely different species like this interacting, it's twice as exciting.”
He added: “A second otter appeared shortly after, and I was able to identify it as one of the family members I follow regularly on the river.
“The one with the fish was the mother, and the other was a pup from last year.
“Neither seemed to be bothered by the cat. In fact, they were totally unfazed by it sitting there!”