Evolvo-Ray

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

Crash Bandicoot
The Evolvo-Ray first appeared in Crash Bandicoot. It was built by N. Brio, though due to his low self-esteem,  Cortex took the credit for it. It was used to mutate: Ripper Roo, Koala Kong, Pinstripe Potoroo, Tawna Bandicoot, and Crash Bandicoot. It was supposedly destroyed when Crash burned down Cortex's castle at the end of the game.

Crash Bandicoot 2: Cortex Strikes Back
The Evolvo-Ray is only mentioned once by Cortex stating that N. Brio invented it, but it is not seen. However, there are four possible new subjects of it, such as: Komodo Joe, Komodo Moe, Tiny Tiger, and Coco Bandicoot. If the Evolvo-Ray was destroyed in Crash Bandicoot, it is unknown how the four came to be.

Crash Bandicoot: Warped
Same as Crash Bandicoot 2: Cortex Strikes Back - it isn't seen, nor heard of. There is only one possible new subjects of it in this game: Dingodile. Fake Crash was not created with the Evolvo-Ray due to him being created in N-Tranced.

Crash Team Racing
Tall, pretty and skinny a lot like Tawna: Isabella, Megumi, Liz, and Ami are all evolved bandicoots. Possibly subjects of the Evolvo-Ray.

Crash Bash
Only one sure major evolution has happened this game, Rilla Roo. Some debate has been made whether the Bearminator was evolved though, so there are possibly two.

Crash Bandicoot: The Wrath of Cortex
Only Crunch had been evolved in this game. However, he may not have been evolved by the Evolvo-Ray for he looks and acts far different than the other evolved bandcoots. He may have been made a more difficult way, for N. Gin even proclaims,"...the super secret weapon you've been laboring over day and night...". thus it would make sense why he is stronger as well.

Crash Twinsanity
The Evolvo-Ray did not appear again until Crash Twinsanity, though only as a prototype version. Cortex had been trying to make it as a kid (before Brio successfully made it). 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 prototype Evolvo-Ray appeared at the end of the game, infused with the Psychetron, where Cortex tried to dispose of Crash the same way he did with Victor and Moritz. However, the machine malfunctions and sends Cortex into Crash's brain. Also, the hated chef Rusty Walrus may have been a experiment.

Crash of the Titans
The new mojo fuled 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,  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; though this was just a quick reminder of the original purpose of Crash's mutation, and what was shown did not actually happen.

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 inventions 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 humanoid features, including the build of Crash in Crash Twinsanity, however, some characters seem to be reversing back into their animal states. This would explain how the characters have changed in appearance over the years.