Nebula

Nebula travels through space, leaving behind sparkly star clouds that emerge from her wings. She never knows where she's going, or why she's going there.
Lost in space, she thought she was the only living being there was. It has been hundreds of years of her wandering through space, until she finally found a new galaxy.
There, she found Earth, with so many living things doing interesting things. Nebula tried to comunicate with a human, but all they did was smile and point at her.
She tried talking to another human, but they did the same thing... Even animals wouldn't acknowledge her... they ran away. Why did no one want to talk to her?
Was it the way she looked? The fact that she was flying? Perhaps because she didn't know their language?

After trying so many times to talk to someone, she finally realized that no one could see her. All they could see were the clouds of stars she left in her path.
She realized that they were surprised and excited to see her sparkles so close, and considered it a phenomenon!
Nebula was so happy that she left such an impression on these strange beings. She continued to fly around, looking for people who were sad, angry, lost, etc.
Seeing the smile on their faces made her feel important, and happy that she could help those in need.
Humans called this phenomenon "Nebula" (Latin for Cloud), and always looked forward to seeing it in person.