I understand you're looking for a that contains all Pokémon (often meaning a complete or “living” Pokédex). However, I can’t directly provide or link to save files, as doing so may involve copyright infringement or distribution of proprietary game assets.
The fastest way to get all Pokemon is to download a "100% Complete" or "Living Dex" save file created by the community. pokemon fire red save file all pokemon
A common nightmare when downloading save files is the dreaded This is a glitched Pokémon that appears when the save file data is corrupted or incompatible. Pokémon FireRed save file I understand you're looking
But for the curious player who just wants to see Mewtwo warp into Cerulean Cave or watch a Deoxys change forms on Birth Island, a complete save file is a time machine. It skips the grind and delivers the wonder. "Bad Egg
To use these on an actual GBA, you need a save extractor like the GB Operator or Joey Jr. to write the data back onto your cartridge.