A Cyclon is an airborne robot that float slowly around the area until threatened. It somewhat resembles a Waver or Halzyn, with its core body (a red sphere marked with a power button) floating between a pair of impenetrable shells that protect its sides. Like a horizontal Spore Spawn, these shells can open or close to expose or protect its vulnerable center. When the Cyclon attacks, its armor disassembles into small bipyramid octahedrons that orbit rapidly around the spinning core, generating a tornado as the Cyclon moves towards the Mii players.
A Cyclon can be instantly killed by shooting its exposed power button. A carefully-aimed shot can kill a passive Cyclon when its shell is open, but missing the shot will cause the Cyclon to react by instantly closing its shell and spinning out of the way. The blast radius of a Charge Bomb or Missile can bypass the Cyclon's armor, killing it even when its shell is closed.
Cyclon Queens are larger Cyclons that constantly summon more Cyclons for her protection. Spawned Cyclons orbit around the Cyclon Queen before assuming one of two formations. When they circle around the Queen, they use their tornado attack. When they form three lines around the Queen, they shoot lasers similar to those used by the Zebesians in Metroid Blast.
Cyclons are common enemies throughout the Assault Mission, appearing in many of the levels. In missions "3. Approaching Cyclons", "6. Cyclon Infestation", "8. Infernal Battle", "12. Subzero Combat", "15. Zebesians Incoming", and "29. On Familiar Ground", the objective is to defeat all enemies, including Cyclons. Mission "7. Destroy 10 Cyclons" is specifically focused on eliminating Cyclons while avoiding Ridley's attacks.
A Cyclon is also a prize, which is placed in Nintendo Land Plaza after being randomly unlocked through the pachinko game. Initially in its armored form, when activated it opens up and unleashes its (harmless) tornado attack with a whirring sound. The prize is found next to Animal Crossing: Sweet Day.
Nintendo Land Plaza
"Cyclons can expand outward to form a powerful tornado, but this exposes their weak spot. This means they're not afraid to show their sensitive side. I do like that in a robot."
- The Cyclon's name is presumably derived from the word "cyclone".