Evolvo-Ray

The Evolvo-Ray is a machine built by Dr. Neo Cortex and Dr. Nitrus Brio to advance the evolution of ordinary animals into sapient beings. It is unknown how Brio and Cortex got the animals to the lab, but they probably captured them in Australia, since the Wumpa Islands are off the coast of Australia. That explains why the animals are typical Australian animals like koalas and kangaroos.

Crash 1
The Evolvo-Ray first appeared in Crash Bandicoot 1. It was built by Brio, though due to his low self-esteem, he let Cortex take the credit for it. It was used to mutate the evil Ripper Roo, Tiny Tiger, Koala Kong, Pinstripe Potoroo,(and many others) Tawna, and the good Coco Bandicoot, Crunch Bandicoot, and, most importantly, Crash Bandicoot. It was supposedly destroyed when Crash burned down Cortex's castle at the end of the game.

Crash Twinsanity
The Evolvo-Ray did not appear again until Crash Twinsanity, though only a prototype version. Cortex had been trying to make it as a kid (before Brio sucessfully made it). (He had stowed away back into the Academy of Evil) Cortex's two test subjects were his parrots: Victor and Moritz. However, instead of evolving them, it sent them to the Tenth Dimension. Nevertheless, Cortex quickly got over the loss of his parrots (the only creatures he didn't "loathe or eat") and continued his studies. A newer version of the Evolvo-Ray appeared at the end of the game, Infused with the Psychotron, where Cortex tries to dispose of Crash the same way he did with Victor and Moritz. However, the machine malfunctions and sends Cortex into Crash's brain.

Crash of the Titans
The Evolvo-Ray had a major appearance in this game. It was used to give Uka Uka a body which was later destroyed by Crash. The handheld ray gun version of the evolvo ray, now powered by mojo, was able to mutate the animals of Wumpa Island into ferocious Titans and make them obey Cortex, N. Gin, Nina, Tiny and Uka Uka. The intro also shows Crash being zapped by the Evolvo Ray.

Crash: Mind over Mutant
The Evolvo-Ray was briefly mentioned by Doctor Nitrus Brio, claiming to be the inventor of the Evolvo-Ray and other stuff that was used by Cortex. Despite this, the Evolvo-Ray made no physical appearance in the game.

Lasting Effects
The Evolvo-Ray has traces of Human DNA in it, according to one game guide. It also states that Cortex intended for Crash to be much taller, referring to the Naughty Dog Crash Bandicoot. The ray could have a delayed effect of either reverse or advanced DNA morphing. Characters like Crash have started out more animal and have slowly developed more personic features, including the build of Crash in Crash Twinsanity, however, some characters seem to be reversing back into their animal states, like Tiny the Tiger, going from a giant muscular bodybuilder to a build more like an animal and resembling his original state even more. This would explain how the characters have changed in appearance over the years.