Metal Gear Solid on PS1 originally had Solid Snake befriending rats.
According to a new video by YouTube channel Did You Know Gaming (narrated by David Hayter no less), game director Hideo Kojima wanted to add more rats into the game, allowing the player to assign them names and raise them as pets.
Rats were apparently the first life forms Snake encounters in the cold of Alaska, and would play an important role in the game.
There's even a reference to this in the Shadow Moses level of Metal Gear Solid 4, where Snake chats to Otacon via Codec about his little, furry friends. This is likely because the rats helped Snake through the vents, but may be a nod to their function as pets too.
Rats also feature in the Sniper Wolf boss fight, and originally if you kept shooting them they would become bigger and bigger. This was removed as it felt like too much of a joke. Instead, the player is called by Colonel Campbell and told to stop shooting them.
These details are from an interview with Kojima by Computer and Video Games magazine in 1999. Did You Know Gaming has delved into other magazine interviews for other little known details.
For instance, a Mariachi character was originally intended for Metal Gear Solid who was an analyst and would give hints on how to defeat enemies after singing songs in Spanish with a flamenco guitar, but it was considered too ridiculous.
In Metal Gear Solid 2, Snake was originally going to have real-time beard growth that could be shaved, something that was later intended for Metal Gear Solid 4. That game also had Snake in a penguin suit known as Antarctic Snake, a reference to 1983 game Antarctic Adventure.
For more weird and wacky Metal Gear facts, check out the full video below.