Fluffy XR-9 is the boss of CloudRun. He is a machine built by bird scientists to fend off the ghosts. The battle takes place on bottomless ground, with three small sinking platforms or five on Simple.
Fluffy XR-9's attacks consist of three "waves". First, he hovers from left to right, back and forth aiming and shooting small rock shots at the bird. When he stops shooting, he will track the bird's movement and attempt to ram into him. After several chase attempts, Fluffy XR-9 will stop and fire four large missiles, spaced equally. The player must jump on top of these missiles to ascend and hit the robot's belly. If the bird gets hit by the front, he takes damage.
The more hits Fluffy XR-9 has taken, the longer his attacks last.
After succesfully defeating Fluffy XR-9 by hitting his belly four times, he will explode a long vertical rain of crystals. Red energy clusters appear on the right side, allowing the bird to proceed to the next screen. The next screen has a gold orb, and a heart can be found by jumping off that platform to the next screen.
Fluffy XR-9's design manual can be found in the Library.