Instructions
Talk to Klungo to begin the battle. He will encase himself in a protective shield. You have to talk to him in all three encounters.
Dodge the potions Klungo throws in your direction and wait for him to drop his shield. At this point, he will drink one of three potions. The potions have one of three random effects -- he either becomes invincible or gigantic, or he splits into several versions of himself.
Adapt to the specific potion Klungo has used. If he becomes gigantic, wait for him to try to jump on you and get out of the way at the last second, then turn around and roll into him. If he is invincible, avoid him until the potion wears off. Then hit him in the brief gap between potion and bubble. If he splits into multiple versions of himself, roll into the version that moves last, as that is the real Klungo.
Hit Klungo three times to defeat him. This is the same for all instances of the fight. Throw eggs at him if you are better with eggs than performing rolls.