After a rather suspenseful display of lighting as the player advances down a hallway the player would most likely be expecting something more menacing but instead they come across the Ratoid Boss on an elevator. This boss is to all intents and purposes identical to the Standard Lv 3 Ratoid except for his higher health.
The player will be on the outer section of the elevator and the Ratoid Boss will be somewhat protected in the middle section of the elevator because the player will not be able to duck and shoot him at the same time. The player can jump over the middle section and attack the Ratoid Boss from both sides but they should also keep in mind that sometimes during the battle the top of the lift where the Ratoid is will sometimes generate electricity that can take away some health. He's armed with the same pipebombs as the level 1, Level 2 and Level 3 Ratoid They are as follows:
- Red Tinted Pipebomb - It will do 10 Damage if it strikes the player; in addition waves of flame will emerge from the left and right of where it detonated; the flames do more damage than being hit by the pipebomb itself and it's obviously more powerful than the red tinted pipebombs the Level 1 ratoid uses. He tend's to use these pipebombs the most in the battle.
- Blue Tinted Pipebomb - The blue tinted pipebombs sprays shrapnel around the place which does some damage before detonation which inflicts Additional damage on the player.
- Homing Pipebomb - It looks almost the same as the pipebomb the player uses however when this pipebomb hit's the ground it will make a beeping noise then explode before splitting into three smaller projectiles that home in on the player much like homing missiles; each projectile does 5 damage.
Another thing the player should be aware of is this is a timed battle. After a certain length of time parts of the outer section of the elevator where the player is will break off giving them less room to work with and if he's not killed in time the player will die. However defeating the boss is fairly straight forward and shouldn't give the player too much trouble and he's actually one of the easiest bosses in the game because of his rather slow rate of fire as it takes him a few seconds or more to throw additional pipebombs which gives the player plenty of time to inflict damage on him. Once Duke kills him he makes his way down to the docks to find Morphix's G.L.O.P.P tanker in the sixth chapter "Tanker Trouble".