| Pokedex Entries: |
| Red | It was created by a scientist afters years of horrific gene splicing and DNA engineering experiments. |
| Blue |
| Yellow | Its DNA is almost the same as Mew's. However, its size and disposition are vastly different. |
| Gold | Because its battle abilities were raised to the ultimate level, it thinks only of defeating its foes. |
| Silver | It usually remains motionless to conserve energy, so that it may unleash its full power in battle. |
| Crystal | Said to rest quietly in an undiscovered cave, this POKéMON was created solely for battling. |
| Ruby | MEWTWO is a POKéMON that was created by genetic manipulation. However, even though the scientific power of humans created this POKéMON's body, they failed to endow MEWTWO with a compassionate heart. |
| Sapphire |
| Emerald | A POKéMON that was created by genetic manipulation. However, even though the scientific power of humans made its body, they failed to give it a warm heart. |
| FireRed | A POKéMON whose genetic code was repeatedly recombined for research. It turned vicious as a result. |
| LeafGreen | It was created by a scientist afters years of horrific gene splicing and DNA engineering experiments. |
| Diamond | A Pokemon created by recombining MEW's genes. It's said to have the most savage heart among Pokemon. |
| Pearl |
| Platinum | A Pokemon created by recombining MEW's genes. It's said to have the most savage heart among Pokemon. |
| Stadium 1 | A vicious psychic POKéMON created by genetic engineering. Its cold, glowing eyes strike fear into its enemy. |
| Stadium 2 | Because its battle abilities were raised to the ultimate level, it thinks only of defeating its foes. |
| TCG | Shining Mewtwo: It uses its highly developed psychic power to defeat its enemies before they even have time to think. |
| Mewtwo: Years of genetic experiments resulted in the creation of this never-before-seen violent Pokémon. |
| Mewtwo: A scientist created this Pokémon after years of horrific gene-splicing and DNA engineering experiments. |
