An elephant is so strong it can stampede humans and other animals to death. But, I'm sure there's an animal that could be pitted against it and win over it. If you had a long enough snake, it could constrict it. Mongoose vs. snake. Snake doesn't stand a chance.
Pigeon. Where I come from pigeons arn't even afraid of humans. We don't mess with them and they don't mess with us. Pigeon will win out of pure intimidation.