The Rocket UFO is the final boss of Metal Slug: 2nd Mission.
Boss Synopsis
When Gimlet and Red Eye have stopped the Rebel Rocket from launching, the rocket's tip seemingly detaches and flies off. The Rocket UFO starts by extending its blades and charging twice at the player. It then retracts the blades and either deploys homing missiles and/or extends a large claw. The whole setup then repeats until it is destroyed. Once it crashes to the floor, Commander Kanan pops out of the Rocket UFO and attempts to fire at the player. One shot is needed to take him down.
Boss Gallery
Rocket UFO's charge attack
Rocket UFO deploying homing missiles.
Rocket UFO using its claw.
Commander Kanan in his desperation mode.