"The Valiant Little Tailor" is a German fairy tale collected by the Brothers Grimm, tale number 20. Joseph Jacobs collected another variant "A Dozen at One Blow" in European Folk and Fairy Tales.
A tailor is preparing to eat some jam, but when flies settle on it, he kills seven of them with one blow of his hand. He makes a belt describing the deed, reading "Seven at One Blow". Inspired, he sets out into the world to seek his fortune. The tailor meets a giant who assumes that "Seven at One Blow" refers to seven men. The giant challenges the tailor. When the giant squeezes water from a boulder, the tailor squeezes milk, or whey, from cheese. The giant throws a rock far into the air, and it eventually lands. The tailor counters the feat by tossing a bird that flies away into the sky; the giant believes the small bird is a "rock" which is thrown so far that it never lands. Later, the giant asks the tailor to help him carry a tree. The tailor directs the giant to carry the trunk, while the tailor will carry the branches. Instead, the tailor climbs on, so the giant carries him as well, but it appears as if the tailor is supporting the branches...