The Fomalhaut is the fourth chronological boss and a supporting antagonist in Thunder Force IV. It is giant flying robot with large "ears" that can act as a means of defense against one of its weak spot. The boss is encountered on the stage "Daser".
The Fomalhaut is roughly 4-5 times the size of the Fire LEO-04 "Rynex", the player's ship. It's most notable feature is a pair of ear-like structures located at the back of the head that will occasionally protect one the boss's several weak spots periodically.
The Fomalhaut is one of the more difficult bosses in the game, it is equipped to two primary weapons, a nose-like blaster that will fire supersonic energy waves at the Rynex, and a pair of four turrets at the bottom of the robot that will fire a series of 4-5 shots that will direct themselves towards the Rynex's estimated altitude in an attempt to destroy the craft; these turrets will eventually be destroyed later in the battle.
At the beginning of the battle, the robot will release a ring of spherical satellites that will begin revolting around the robot as a means of defense, as they will block off firepower. The player will need two shoot a total of two weak spots in order to disable these spheres from getting into the way of there firepower: a horn located on the head of the robot (which will occasionally be obscured by a pair of ear-like mechanisms as a means of second-line defense), and two tank-like structures in front of the robot's torso (which will need to be damaged twice in order to disable the satellites). Each time one of these structures gets destroyed, the spheres will be launched outwards towards the player, who will have to evade them to prevent harm.
After both of these structures are destroyed, the Fomalhaut will stop creating rings of these satellites and instead release individual ones in an attempt to ram into the Rynex, the satellites at this point are destroyable, but the player will have to use a lot of firepower to do so. On harder difficulties, these satellites will also fire at the Rynex.
The Fomalhaut will continue to use supersonic energy waves and fire semi-homing laser blasts as the Rynex continues to battle the giant machine. Its weak spot at this stage will be the bottom region of the torso were the four turrets are located. Successfully destroying this layer will disable the homing lasers. Afterwards the upper region of the torso will become the weak spot and the Rynex will have to provide firepower onto that area of the Fomalhaut whilst evading the energy waves and satellites.
After the torso gets destroyed, only the head of the Fomalhaut will remain, the Rynex will simply need to only provide a small amount of firepower onto the head and then the battle will end. Watch out though, the Fomalhaut will still fire energy waves and deploy satellites even though only the head is remaining.
At the end of the battle, the Fomalhaut will explode. Its head and "ears" will separate and fall into the sand below and will disperse as a means of retreat.
- Fomalhaut gets its name from the brightest star in a constellation known as Piscis Austrinus, or "Southern Fish", which depicts a fish collecting the water from the pot of the nearby constellation Aquarius.