I also wrote a back story for the Cosplay. It helps me develop the look of the character.

Vault 64 is one of the many vaults created by Vault-Tec to shelter it's inhabitants from nuclear extermination. Many of the vaults had special purposes. Some were merely meant to house people in safty from the explosion and remaining fallout of a nuclear attack, but others where meant to conduct experiminets and even be the expiriemnt itself. Vault 64's purpose was to conduct experiments on the effects of radiation on animals. The Vault overseerer and one of the prominant scientists in the field was a man known as Dr. Toadstool. His daughter, Peach, was an exceptional scientist/biologist as well and was the head of the department of Nuclear Biological and Metazoic Engineering. Her fisrt successful creation was a radiation mutated turtle species she named Koopas. She also had a hand in the creation of the mutated mushroom creatures known as Goombas (Primarily created by a Professor E. Ghad). Her most successful experiment came when she was inspired by her work with the mushrooms where she created a sintiant mushroom headed speices of creatures knon as the Toads (Partially named for her surname Toadstool). The Toads showed signed of intellegence and were even able to speak in a primative fashion. Eventually they would come to revere Peach as their royalty, calling her "Princess". They even made her a beautiful Pink dress and a crown embedded with pink and blue jewels. After their creation, she spent most of her time with them, studying, learning, and teaching. This made her far less intellegent creations, the koopas, jelous. One particularly more so than the rest, an extremely large, spikey shelled Koopa known as Bowser. He was Peaches first creation. After him, she was able to alter the dna strain so that the other koopas were smaller and more docile. Koopa was kept in a subvault as he was known to lash out and attack anyone but Peach. From his vault he managed to dig into the walls and descovered an adjcent cavern where he created his lair. He was also able to communicate with his Koopa underlings (They treated him as their leader or King Koopa) via small tunnels they created and connected to the air ducts. When he discovered the Toads were created and Peaches infatuation with them, he decided it was time to attack. He managed to recruit the help of the Goombas as well as a few otheir Engineered creatures (Known as Shy Guys, Bullet Bills, Bob-Ombs, Chain Chomps, and Spineys) The Vault Dwellers panicked and retreated to another sub vault equipped with Cryotubes. The remaing vault dwellers locked themselves in behind the extrememly thick walls of the subvault and released a contigency gas to kill everything else left in the Vault. They then went into a cryo sleep set for 200 years hoping the creatures would have died off by then and the remaining gas disperesed. Amung those that survived were two plumber brothers by the name of Mario and Luigi. After 200 years the cryotubes released their inhabitants to find the cryo vault untouched. As they exited into the main vault however, they find that not only had the creatures survived, but the contigency gas mutated them further. The gas only mutated the creatures further but not physically. Their intellegence incresed. The Toads managed to seal off the lower half of the vault, surviving off the hydroponics lab and growning their own food. The Koopas and other creatures learned to speak but were still of a lower intellegece than the Toads. The Vault Dwellers decided to try and fight their way out of the vault. Once they opened the upper vault door, the creatures attacked. They killed all the vault dwellers but Mario, Luigi, and Peach. Peach was kidnapped by Bowser and reatreated into his now massive lair. Mario and Luigi fought their way to him and saved Peach. They didn't kill Bowser but managed to escape the vault and seal him and all of his creatures in but not before helping some of the Toad survivors escape. They have been wandering the wasteland together ever since.