King Eelongo resembles a titanic brown stone (or mechanical) Eelongo. He is obviously aged, as his hide is cracked and numerous gaps have appeared in his body, revealing his weak skeletal spine. He reappears in Stage 9 of Volcano Valley, this time in a shade of purple, and is slightly less damaged-looking.
The screen will start side-scrolling as soon as the battle begins. King Eelongo will attempt to charge into the Kirbys. He will emit a few air bubbles before his charge which can be used to refill the Kirbys' air meter should the need arise. Numerous holes exist on both the top and bottom of the stage that can be used to take shelter. They must also enter these holes in order to get a good vantage point for attacking his segmented midsection, which serve as his weak points. The Eelongo has five segments on either side, two of which have already been destroyed and a few more that have been cracked. It takes two his for each complete segment to be destroyed.
After one of the segments is destroyed, it reveals an inner spine which is spiked. If the Kirbys miss the Eelingo's exterior and hit the spine, they will take damage. As the battle continues, blocks will begin to appear which prevent the Kirbys from going into the holes and King Eelongo will pick up speed. Clam shells also appear in the holes, which can be flicked into to reveal three air bubbles. After all the segments are destroyed, King Eelongo will be destroyed and reveal a door. He reappears in Stage 9 of Volcano Valley. Not much had changed, but blocks appear sooner, and the stage is in murky water, which saps air much quicker.
King Eelongo's name is most likely a play on the words eel and long, as well as the word elongate.