She spawned from a fairy ring of mushrooms in the forest. Since then, Marcie has wandered the planet to seek adventures.
She has remained the same as the years pass. Many report seeing her in various locations where she shouldn't be, but no one can confirm or deny it.
No one knows how Marcie came to be. One moment, there was a giant circle of Fly Agaric mushrooms in the forest. The next moment she was there, and the mushrooms disappeared.
A family found and raised her when she was a pup. Much as she loved them, she knows nothing lasts forever with her. She could only watch as they grew old while she remained the same.
Sometimes she will come around and check on their descendants in secret.