Another angle is that maybe "1636" is a part of a file name, indicating a specific build of the game. Alternatively, it might be a typo for another term. If "squirrels" is a mistranslation or typo for another Pokémon, like "Silcoon" or "Sylow", but that's a stretch.
This is the anomaly. There is no Pokémon called “Squirrel” (except the fan-nickname for Pachirisu or Greedent, which came later). 1636 pokemon fire red u squirrels rom extra quality
The number does not correspond to a standard Pokémon ID (the original 151 Pokémon go up to 151). Possible interpretations: Another angle is that maybe "1636" is a
"Squirrels" is the handle of the individual who originally "dumped" (copied) this digital version from the physical cartridge. In the community, this tag guarantees the ROM is "clean"—meaning it hasn't been pre-modified or corrupted. This is the anomaly
: Most hacking tools and modern patches (UPS/IPS) use the memory offsets of the v1.0 ROM. Using a v1.1 ROM or a different dump will often cause the patch to fail or crash the game because those versions shifted the internal memory addresses.
The most boring, yet likely, explanation: A user in 2009 was multitasking. They had a folder of animal wallpapers (squirrels.jpg) and a ROM folder. A copy-paste error merged the filenames. The "extra quality" part was a boast added to attract downloaders on peer-to-peer networks like LimeWire or eMule.