Comb jellies, also known as ctenophores, have rows of comb-like plates that they use for locomotion. As they swim, the combs refract light and have a glowing rainbow effect. Some species are bioluminescent, meaning that they can produce their own light and flash on and off when disturbed.
Guess what else they sometimes do when disturbed?
That’s right- they ink!
…Just like sea hares. That one was too easy.