Dunkleosteus Fish

The Dunkleosteus Fish is a character appearing in Never-ending story.

Never-ending story
The Dunkleosteus Fish made friends with Water-breathing Spiderman after the latter got transformed into Banana-man III by eating a fruit cake. The fish then became Batman VI.

Together, they fought the Evil Pink Frosted Sprinkled Donut, but the donut won the fight and ate them for breakfast. SpongeBob SquarePants then ate the donut and repeatedly died and came back to life.