The Sea Satan (also known as "Sea Devil") is the fifth boss in Metal Slug 4.
This huge submarine is used by the Amadeus Syndicate. It can destroy ships with ease.
It can also kill any personnel aboard using its Gatling Gun and dissipate it's target using it's missiles. It can either stealthily destroy a submarine and ship or aggressively engage them head on.
There will be rebels getting out of the ship everytime during the fight, trying to prevent the player(s) from damaging and destroying the ship, while the soldiers who control the turret mans a rocket launcher which also hides a minigun at you. After some time, it will dive under the sea and begin launching rockets. It also gets support from the Bura Gariae during the fight.
- Like all Metal Slug 4 bosses, it was made using old sprites from previous Metal Slug games.