Despite being ostensibly based on a Wiggler, it bears little resemblance to them, though it has a similar "enraged" state. It has five glowing orange eyes, a cyan and pink plasma globe embedded into each segment including the head, yellow electricity-producing rods surrounding said globes, Mechawiggler has spindly insect legs and a mouth that resembles an electric plug.
Mechawiggler is initially found covered in electricity on the lightning rod of New Donk City Hall, where it uses its plug to absorb the city's electrical power. Once Mario reaches the top, it briefly crawls around the rod a few times before stopping and shrieking, followed by it charging Mario off the side of the building. Mechawiggler then proceeds to pursue the falling Mario down the side of the building.
Once defeated, Mechawiggler, covered in electricity, shrieks one more time, before exploding from tail to head, releasing a Multi Moon. After defeat, a piece of Mechawiggler crashes in Mayor Pauline Commemorative Park and can be Ground Pounded to collect a Power Moon.
In order to damage the Mechawiggler, Mario must capture the Sherms with his hat and use their ability to shoot at the various segments on Mechawiggler. While on the wall, the Mechawiggler will also fire energy balls at Mario from his segments, which can be destroyed by shooting with the Sherm. After all of the segments of the Mechawiggler have been broken, his energy will drain, so Mario can shoot him.
After taking enough hits, the Mechawiggler will enter an enraged state and charge directly at Mario. In this state, the Mechawiggler is invulnerable to damage. Also, it will teleport in and out of the arena in an attempt to mow down Mario; the location of where the Mechawiggler will appear is indicated by a line.
The second phase is similar to the first other than the charge attack, but after it takes enough hits while in his calm form, the Mechawiggler will blow up and grant Mario a Multi Moon.
In the Mushroom Kingdom rematch, two Mechawigglers appear, and their intro has them crawl down the building one by one after Mario lands in the arena. Their charge attack involves them splitting up and charging as separate entities, and their combined form therefore has extra segments. The two Mechawigglers can support each other by transfering their power between each other in their combined form, allowing them to survive having their partner being drained of power. Sometimes, the two robots can fire pink blasts of energy in their combined form. These pink blasts will eventually dissipate on their own after a certain amount of time-only for more yellow energy blasts to rain down shortly afterward.
- Just like his regular Wiggler counterpart, the Mechawiggler enters an angry state when first damaged.
- Mechawiggler is one of three bosses in Super Mario Odyssey that is defeated in more or less than three phases, going down in two phases. The only other bosses that share this trait are the RoboBrood, which goes down in four phases, and Topper (first battle only), who has two.
- The battle bears a slight resemblance to Star Fox Assault since the player can enter a tank fire upon the boss. (Fox McCloud uses a Landmaster while Mario uses a Sherm.)
- The battle also bears a minor resemblance to the arcade game Centipede by Atari.