What's wrong with Ursa major? Is there really such an animal in the sky?

LS is not exact. The spoon made up of the Big Dipper is a part of Ursa Major.

This "bear" in the sky comes from Greek mythology.

Caristo, a beautiful woman, was loved by Zeus, so she was jealous by Hera, turned into a bear, and was hunted by her son who was a hunter. Zeus couldn't bear to see their mother and son cannibalize each other, so he raised karis in the starry sky to become Ursa major and her son became Ursa minor.

LZ, if you are interested, take a look at Greek mythology ~ most of the legends of constellations come from this.