He-Man and the Masters of the Universe

Today seems to be "back to the good old days" day. Or rather, "let's remember the cartoon from my childhood" day.

So yet another cartoon series, one of those which I really loved, was He-Man and the Masters of the Universe.
The hero is He-Man, and he transforms from Prince Adam into his hero form by calling out "By the power of Grayskull, I have the power". And his cowardly cat Cringer becomes the fearsome Battlecat.
He-Man and the Masters of the Universe on Wikipedia