Soulskill from the i-don't-eat-greens,-food-eats-greens dept.
SilverEar writes "Imagine a creature that swims and preys on others, but once it eats a certain kind of plant, that plant grows inside it, causing the predator to lose its ability to prey and start using sunlight to make its food. Its preying mouth is replaced by an eye that is needed to find sunlight. This is the Hatena ('enigma' in Japanese). The kicker: when Hatena reproduces, one offspring is a peaceful photosynthesizer with the sun-seeking eye, while the other is yet again a predator with a voracious mouth."
"Someone's been mean to you! Tell me who it is, so I can punch him tastefully."
-- Ralph Bakshi's Mighty Mouse