We have a small pond and there are many tadpoles. I bought a dozen small goldfish today and once acclimated we put them in the water. The water is very clear and my children and I watched in shock as several tadpoles attached themselves to the goldfish and literally weighed the goldfish down where they couldn’t even swim away. My little boys put their hands in the water to get the tadpoles off the fish. We watched for over an hour as these tadpoles kept attaching (biting) the goldfish. We went in the house for an hour and when we came back there we’re 2 fish dead with scales missing off the sides and bellies The tadpoles we’re feeding on them. These poor fish. I had no idea this would happen And wouldn’t have believed it if I had not seen it with my own eyes. These tadpoles are aggressive and they are much smaller than the fish. Probably 20 tadpoles to 1 fish.l in size. So yes tadpoles have the potential to eat and kill other fish in your pond, especially if 10-20 attach to an even larger fish.