I first thought of the animal and as I was replying to your post, I thought of the army Seal XD
book seals also came across my mind but not magic seals..
It was a very old video..
basically the baby seal (or sea lion.. can't remember) is floating on a piece of ice, 3 dolphins came to eat (can't remember.. do dolphins eat baby seals?) it and before they do that, they toy with him as he try to escape but rolls backwards, sideways, and almost fell into the water. (the dolphins use the waves to move the piece of ice)