Items: Life Gem
This is the final area you'll want to explore in Eggplant Caverns. When you enter, you'll see a mysterious crystal hovering over a large stone pedestal. Puku and Parin are alone in the area. He tells you that there must be a switch to lower a gate that rises nearby. He suggests that four pillars in the area may hold the key. Go ahead and drill the holes positioned at the base of each pillar. Once you've succeeded, you'll trigger a cut scene. Some interesting plot details that you should have guessed by now will be revealed.
Once the plot sequences end, you should continue through the door that opened. When you appear in the next area, you'll be at the start of a long hallway. Follow it forward and toward the left, where you'll find a glowing platform. Ride it to the top, then step forward. Now you'll get to battle the prince as he rides around on his beast, Giga.
Boss Battle: Giga
This is just the warm-up battle, so you shouldn't have much trouble with it. Giga stays in place at the center of the arena and swings his arms around wildly, but for the most part those attacks are unlikely to even touch you. He'll posture for a bit, then cause a bunch of boulders to fly up from the air around him, then all converge on the place where he waits.
Make sure that the boulders don't harm you when he's doing that, then start drilling them with short drill attacks to chip away at his shield. Note that during this time, he will flash purple. He's invulnerable as long as that is happening, so focus on the boulders instead of his body. When you've removed enough of the boulders, the remainder should fly away. They'll start to tremble before that happens, so back out of the way so they don't harm you.
Once the boulders are gone, Giga will be a dark blue color and vulnerable to your attacks. That's your hint to move in and start using charged drill attacks. You don't want to power up the drill all the way, just partway so that you can get off a few nice bursts. As you continue to wail on him, he'll eventually start to gather boulders around him to repeat the process you just went through. You'll have to repeat the steps around three or four times, but you should eventually drain his life meter completely. Victory is yours. At least... sort of.
The battle with Giga is over, but the Prince is far from finished. As his beast fades away, he'll jump down to face you himself. Parin is delighted. The true battle has begun.
Boss Battle: The Prince
This battle isn't much more difficult than the one with Giga, so don't worry too much. The Prince is much more mobile than his mount was, and his attacks can do a fair bit of damage if they hit you, but his life meter isn't as robust as you might expect. You'll probably want two or three chocolates to carry you safely through the encounter, but that should be enough.
Basically, the Prince wanders around the arena in wide, quick circles. He'll charge you at various points. What you want to do is get in close enough to use a targeted attack, then follow that up with as many launch attacks as you can manage before the Prince retreats. He'll either back away, or head to the edge of the arena and disappear that way. In either event, you can expect the next attack to come from the center of the arena. Always look there for the Prince's approach.
Also, don't walk around at all unless you're getting ready to jump and use a target attack. Instead, you should be using the dash guard move to get around the arena. That way, you're not caught in the crossfire if the Prince decides to use one of his projectile attacks (he has two). The same move also helps you to avoid him when he starts whirling around like a tornado, blade extended. During such times, you can and should use a targeted attack to put an end to his rampage and to continue draining his life meter. All things considered, it's a rather simple battle. Cream was harder.
When you defeat the Prince, he'll shout "I was so close!" and then vanish. The standard LIFE GEM
will appear at the center of the arena and when you touch it, the level is completed.
The game isn't, however. The Prince says he was just buying time. The scene flashes back to Monster Village, and even to Tiese Town. Rumbling shakes the very planet. New events transpire, and it looks like you might have another battle for a moment, but that's not the case. You're granted a reprieve, and now a new area is available on the world map. The game will allow you to save your progress. Do so, then head back to Tiese Town to stock up on healing supplies. Also, make sure that you use the Life Gem item so that you will have the maximum amount of health available when you head into that final battle. When you're done, go ahead and visit the next dungeon.
NEXT: Oblivion Abyss