20 Video Game Bosses You Must Defeat Before You Die

8. Metal Gear Rex (Metal Gear Solid)

For my money easily the hardest boss in a Metal Gear Solid game, Metal Gear Rex is the prototype weapon you've spent all of the game up to this point trying to stop. However, after spending far too long messing around with a key card that changes form according to temperature, you eventually activate Rex by accident, so Liquid jumps in the pilot's chair and you have to face him down. There are several keys to winning this battle, but above all else, you need to make sure you've stocked up on rations, stinger missiles and chaff grenades. Chaff grenades will ensure homing missiles can't reach you, and the stinger will deliver massive damage to him, though when the second part of the battle begins, Liquid will begin tracking you himself, and chaffs are virtually useless. Instead, the key is to stay out of his line of sight by keeping close to Rex, but also keep moving to ensure that Rex doesn't tread on you (which is an instant Game Over). Keep firing stingers and eventually, if you're lucky, you'll bring the big boy down. On the plus side, the remaining two fights in the game seem considerably easier after you've taken that beast down.