Before having the chance to defeat Bowser on Moon Kingdom, the Broodal Group will appear once again, this time in their giant RoboBrood Machine. The fight with them will begin with RoboBrood shooting firing cannonballs form its chest. After a certain amount of bombs, it will also spit out a random Pokio. Quickly capture the bird, using it to send the cannonballs back at the machine.
By doing so, the metal outer shell on the robot's legs will explode, knocking it back and exposing one of the Broodals on top. Flick yourself (still as the Pokio) up the legs of the robot, poking the exposed Broodal to deal damage. Repeat this process again after you do, this time avoiding the giant steps of RoboBrood. Blow up the legs again to knock the robot down once more, taking out a different Broodal this time around.
After this, RoboBrood's legs will begin glowing as it begins to charge at you. It will take several moments of running in place before it begins moving forward, so use this time to plan your dodge in order for it to run right by you. After it begins slowing down, the robot will begin launching spinning firecrackers at you. These too can easily be pecked away, and after doing so, it will resume shooting bombs like before. Deflect these bombs again, exposing the Broodal at the top of RoboBrood. Attack this Broodal to proceed to the final phase of the battle.
In the final phase of this battle, RoboBrood will advance quite rapidly, forcing you to constantly move to avoid it. Dodge the spinning firecrackers like before, waiting for your chance to attack when it reverts back to shooting more cannonballs. Do just as before to expose the final Broodal, attacking it to defeat the mechanical beast once and for all.