This Seeking Tech guide will show you how to get Believe It or Not trophy and achievement in the Master Collection version of Metal Gear Solid 3: Snake Eater.
This will unlock when you “catch a Tsuchinoko (mythical serpent).”
This creature can’t be caught normally. Instead, it can only be caught by using a mouse trap.
To get this, play through the game until you meet Granin at Graniny Gorki Lab. He will give you a key card to unlock the red door at the Ponizovje Warehouse. When progressing through the game, make sure you explore each area carefully to find mouse traps.
There should also be a mouse trap in the small room on the upper floors of the Ponizovje Warehouse.
Once you are ready, head to the northwest exit at the Ponizovje Warehouse to go to Graniny Gorki South.
At the entrance, place every mouse trap you have on the ground. Afterwards, head back to the warehouse and then immediately turn around to return to Graniny Gorki South again.
The mouse traps should now be filled with captured animals. Go into first person mode to see if a Tsuchinoko is among the captured. If you don’t see it, pick up the captured animals (you may have to eat or dispose of any food items to make room).
Re-place any of the mouse traps you picked up in the same spot and then repeat the process until you capture the Tsuchinoko to unlock this trophy and achievement.
You can find a video guide below to see the process in action: