Do you know any good dream myths, legends or stories?

I can't think of any other myths about who give us dreams.

I could think of one other myth related to dreams though. If you die in your dream then you die in real life.

This is a great question, and you have to keep in mind that the definitions of "myth" and "legend" are pretty fluid - oftentimes, they are used interchangeably. "Jason and the Argonauts," for example, might technically be a legend, but is often included with other Greek myths. In the study of literature, we usually think of a myth as a story with religious significance that explains how the world works, how something came to be, why certain things are done in a culture, or to describe the history of a nation/society/tribe/etc. We usually think of a legend as a story about a specific person (not necessarily a real person) and their adventures and exploits. The stories of King Arthur are a little bit of both, and you can safely call them legends or myths. Some of the stories are about the amazing deeds of the knights, and some are about mystical religious/spiritual ideas (the Holy Grail, the second coming of Arthur, etc). The idea of Groundhog Day would be considered a superstition. It's not a narrative, it's just a little bit of "wisdom." It's like not stepping on a crack or you'll break your mother's back.