Walkthrough: The battle with Mechawiggler will start by it moving about the wall. Look for the two Sherms found in the arena, capturing one to defeat the other after you do. After that, begin attacking Mechawiggler while you avoid the projectile orbs it shoots at you. Aim and shoot to cause damage to the creature. If you hit the segmented part of its body, you'll douse the lights found here on it. By knocking its whole body out, you'll expose the creature, allowing you to fire at will.
The next phase will begin with Mechawiggler entering a wormhole. It will try to attack you this time by shooting electric bolts out of the wormhole, so make sure to dodge as many as you can. Make sure to keep out of the rays that begin to turn red, as Mechawiggler will quickly attempt to ram you, and it will do this several times. After returning to the walls, it will shoot all the more orbs at you. After knocking out the spheres one by one, Mechawiggler will extend its body and move much quicker. It will also fire more attacks at Mario.
When Mechawiggler stops to charge up, that's the best opportunity to attacks as many of its body parts as you can. If you don't finish it off in this one shot, it will retreat back into the wormhole and you'll be back at step one. If this happens, it will do as before and continuously try to ram you. From there, the final phase will repeat itself, giving you another opportunity to finish it off. After picking apart every part of Mechawiggler, unleash one more attack to defeat it and win another Multi Moon.