Popper

 Popper is a virus from the MegaMan Battle Network series. It is invincible until it drops down from wherever it hides and attacks. They attack with homing wooden spikes.

Popper
 Rattys are orange with an orange head. They also have a red light on top.

Popper2
 Ratty2s are brown with a blue head. They also have a dark orange light on top.

Popper3
 Ratty3s are gray with a gray head. They also have a blue light on top.