The sea is full of fishes, as a human proverb says.

These fishes come in all shapes and sizes, and many of them are very similar to humans: mermen and sirens.

You are one of the biggest mermen that live in the sea. Your ancient frame travels the coldest waters of the world in winter, living mostly in solitude. But in spring and summer, this changes: it is the reproductive season, and you are called to take part in it too. So you migrate from the cold waters of the poles to tropical waters, where every year you mate and father many tadpoles.