I haven't played any MGS games in many years, but I recall playing a particular installment of it where one of the side missions or easter eggs is that you have to try and find and capture these snakes in cages I think. I may be misremembering some of the details, but I do remember that the snakes were involved somehow.
I've researched all of the MGS games and I can't figure out which one I'm thinking of - anyone here have a clue?