It will start off small and blue, but if it takes enough damage, it makes a laughing noise and grows larger, also turning yellow in the process. It will then proceed to turn into a larger version of itself with a reddish color. While the Nagagog is changing into a larger version of itself, it will not take any damages from attacks or items.
Its health decreases much easier when it is in its larger form. It has three attacks: tripping and falling on the player, jumping while spinning or slapping the ground near it. To turn a Nagagog into a trophy, it is recommended to use your Trophy Stand while the Nagagog is on its largest form, because you will have a decreased chance of missing. However, it still needs to be weakened before throwing the stand. If you turn a Nagagog into a trophy, it will have all forms.
An enemy that might be considered sumo-wrestler shaped, with a funky, decorative twirl on its head and a cute little mouth. As it takes damage, its body increases in size through three distinct levels. Wow, it's almost like a sumo wrestler climbing the ranks to become Yokozuna! Along with the size increase comes a change in color as well--blue, yellow, and red.