Parasitis

Parasitis is the main antagonist of the 1989 NES game Abadox. It is a giant alien that the entire game takes place in.(except for the fist half of the first level.)

Before Abadox
Abadox is a planet that gets eaten by Parasitis in 5012. after which the monster takes the form of the planet. it also has a princess inside of it named Maria who the protagonist, Second Lieutenant Nazal, has to rescue.

Attack Pattern
The entire game is pretty much him keeping the player at bay. since many of the bosses are connected to him or grow out of his body, it can be assumed that they are controlled by him or are a part of him. Such bosses include the first, second, third, possibly the forth, and sixth.
 * 1)  The first boss is called deathface, and it grows out of the wall at the end of the first level. It has 2 eyes attached to long optic nerves that move up and down opposite each other and shoot shots. despite the eyes being out of the sockets, it can still blink it's lids. And when its eyelids are open, an enemy comes out that can be destroyed. it also spits 3 diamond shaped projectiles put of its mouth.