If a patch fails with a "checksum mismatch" error, you likely have the wrong version of FireRed. The correct Squirrels 1.0 ROM should have the following CRC32 hex code
Play experience
If you are simply curious about the concept of a squirrel-themed Pokémon FireRed, consider supporting legitimate creators who have made similar (and documented) hacks, such as Pokémon Squirrel Edition or Fire Red: Nutty Version . 1636 pokemon fire red usquirrels rom