Does mewthree actually exist?

I think around when red and blue released in japan

Mewthree isn't an official Pokémon but a popular fan creation, a rumored third clone of Mew after Mewtwo, appearing primarily in fan games (like Pokémon Chaos Black), fan fiction, and urban legends as an even more powerful evolution or DNA fusion, though it did appear in the Pokémon Pocket Monsters manga as a transformed Clefairy. Its concept stems from fan desires for a stronger Mew clone, often depicted with visual traits of both Mew and Mewtwo, sometimes as an armored form or a completely new creature.

(Copy pasted from Google)