Rainy Days is the mother of Pink Eyes protagonist, Puppysmiles. She worked for Stable-Tec up and down Route 52 before the war and sometimes took Puppysmiles to work with her.
During the War
Rainy Days was employed by Stable-Tec and worked extensively along Route 52. She would often bring Puppysmiles with her, which is how Puppysmiles learns the codes needed to access various terminals and facilities 200 years later.
When the Megaspells fell on the Last Day, Rainy Days was at work, and Puppysmiles alone at home. Rainy Days knew Puppysmiles was either dead or hopefully in a Stable, safe and sound, which was one of the driving forces that helped Rainy Days continue to go on living and helping ponies.
After the War
She spent her time after the bombs fell travelling Route 52 & teaching the ponies there how to survive in the new radioactive environment. She travelled through nearly all the major settlements of the Big 52, stopping by the 165th Brigade headquarters in what would become the Salt Marshes and waiting at Tunnel Town briefly. She continued to move along Route 52, stopping by an airfield she and Puppysmiles had visited at an earlier time. Rainy Days next set up a camp at Ivory Tower.
Using the resources at Ivory Tower, Rainy Days helped organise the surviving ponies along Route 52. She left Ivory Tower afterward and established Rainy Camp, later renamed to Broccoli. Her final stop along Route 52 was Emerald Shores, which overlooked the sea. Rainy Days made it to the end of Route 52 where a kind soul buried her and placed a marker near a cliff. A chest full of Rainy Days' belongings ended up on the beach behind her grave. Puppysmiles would discover her mother's grave at the end of her journey.
Rainy Days left numerous messages along Route 52, which Puppysmiles would stumble upon as she made her way down Route 52. Rainy Days also met Molten Gold during her travels and took back some Rad-X he had tried to steal.
Rainy Days was a purple coated mare with an orange mane and a cutie mark of a rain cloud with a few droplets underneath it.
Rainy Days was a compassionate pony, travelling the length of the Big 52 to help the ponies living along the route learn to survive the apocalypse and all the new dangers it presented. She was also a caring mother who loved her daughter greatly.
Because of Rainy Days, hundreds--possibly thousands--of ponies' lives were saved along Route 52. These survivors would pass on the survival techniques taught to them and allow life to continue along Route 52. The Ghoul, Molten Gold, would remember Rainy Days and try to convince her daughter to go on living.