Many, many years ago, long before Dream Valley itself, there lived a young colt called Baby Nightglow. Baby Nightglow was an average pegasus foal who lived with his mother Sunrise and father Nightglow in a small herd. Ponies are very rare, so when one of the stallions announces that their herd is joining with another herd, everyone is elated. Baby Nightglow is most excited about the chance to meet another foal. As it turns out, there's something very special about this pony: She has a rainbow-coloured mane and tail.
Chasing the Rainbow tells of Baby Nightglow and his friend Baby Featherfall as they discover Dream Valley.
This fanfic provides examples of:
- Adaptation Name Change: The sea ponies are not identified as such. They're "water ponies".
- Ambiguous Gender: Water ponies are androgynous looking and sounding. It wasn't known that Skydancer was male until Reed Dancer mentioned it.
- Animal Religion: Ponies worship the rainbow. Surprisingly, even water ponies worship it. Rainbow ponies are considered blessed and chosen by the rainbow itself.
- Crying Critters: The ponies act as Partially Civilized Animals but are able to cry.
- Dead Fic: The story hasn't been updated since its 8th chapter in May 2003.
- Death by Childbirth: It's mentioned that ponies rarely conceive and many of these foals die in childbirth. In the latter case, the mothers usually die as well. Baby Nightglow vaguely remembers a mare named Acorn who died in childbirth.
- Eskimos Aren't Real: The ponies don't believe that lions are real.
- Furry Denial: Subverted. Baby Nightglow says that "Animals don't talk", realizes what he said, and adds in "Except us".
- Meaningful Rename: When a pony becomes an adult, they not only receive a new name but their colors change as well. Ponies are born looking like either their mother or father, and they're also named after one of their parents, but they receive a new colouring and name upon reaching adulthood.
- Naming Ceremony: When a baby pony grows up, they receive their new name and colors in a naming ceremony.
- Oh My Gods!: The Rainbow is revered by ponies and ponies swear to it. For example, "by the Rainbow", "what in the Rainbow", and "Rainbow knows" are used.