Hooplagoon is a Boss from Kirby and the Rainbow Curse, appearing at the end of both Yellow Dunes and Orange Woodland. It was built by Claycia using ancient clay, and tasked to destroy any intruders it encountered.
Hooplagoon is a round creature, similar in shape to a Blado. It has four rotating shields around it (one of which is metal) and also sports golden goggles over its two eyes. Underneath the shields are a number of spinning gears and cogs which power the beast, and allow it to fire lasers from four prongs between the shields.
Hooplagoon attacks by floating around the arena and firing lasers from its prongs. It can also generate an electric field around itself in certain instances.
To defeat Hooplagoon, Kirby has to dash into its shields to break them one-by-one. Every time a shield is broken, Hooplagoon grows in size, making the remaining shields more difficult to hit. The last metal shield can only be broken using a Star Dash. As such, the main aim for Kirby is to avoid Hooplagoon's laser and spark attacks, then aim for an intact shield when the coast is clear.
Hooplagoon is fought twice. The second time, it bears a different color scheme and has a scuba mask, as the fight takes place underwater. Apart from those details, it is largely the same as the first.