Include pictures if you can, please! That way we can all get the full effect!
To open the thread, though I'm sure I have way more to list, I bring you the Angler Fish. Fans of Finding Nemo will be familiar with this one, but may not know the weirdest thing about them.
Be glad you are human.When scientists first discovered these fish, they kept wondering why all the fish they captured where females. However, after some time they noticed small “growths” on the females skin that, upon closer inspection, turned out to be males. The tiny males actually only live to find a female. Upon encounter, a male bites into her skin after which the tissues of the male and female become completely fused together so that their blood vessels join as one.