The Feeder is the second boss for the game Metal Black, and is one of the vestiges of the Darius roots of the game as Darius III.
Feeder originally appears disguised as the Earth's Moon on the background during the whole level, "watching" the player, until it reaches the real moon, then Feeder's "Lunar Egg" (or disguise) color changes from gray to yellow and gets closer to the player, where it cracks and Feeder hatches, breaking free (and vulnerable to the player attacks).
Feeder's attack begins with a constant beam shooting, then it will move out of the screen by flying to the left, then it will reappear and will bounce down diagonally from right to left, dropping grey spheres, which will take random positions. once Feeder is on the right side of the screen, it'll send a "Newalone Picking Worm" to pick the falling Newalone particles, to power himself up, while the worm makes the job, Feeder will fire a laser from its tail, bouncing on the balls in random patterns. Once he finishes firing, he will fire three missiles. then it will leave the screen again, but firing another three missiles before it leaves. Then he will repeat the "reapear and bounce back and forth" again, after this, Feeder will fire his Max Beam attack, this is where the player (if he/she has the beam level at full power) can counter Feeder's attack.