Instructions
Travel through Frozen Furnace, the game's fifth world, to reach Klungo, the boss at the end of the world. At this point in the game, you've already fought Klungo twice and you'll fight him one more time before the end of the game.
Avoid the potions Klungo throws at you by moving quickly around the arena and jumping when necessary. Do not approach Klungo when his shield is up; touching the shield causes you to take damage.
Wait for Klungo's potions to miss you three times, at which time he deactivate his shield and comes after you. He is invisible while his shield is deactivated, but occasionally flickers into visibility. Use these occasional flickers to deduce his position and attack him.
Hit Klungo once; he'll deploy a pair of small gremlins who'll latch onto you and begin draining your health. Let the gremlins latch on, then run in tight circles until you shake them off and they die. After the gremlins die, Klungo reactivates his shield and resumes throwing potions at you.
Repeat Steps 2 through 4 through two more cycles. As you repeat the steps, Klungo throws more potions and releases more gremlins. Only allow two gremlins at a time to latch onto you; shake those off before letting two more latch. After completing the cycle two more times, Klungo retreats and leaves the final Mumbo Totem.