Honestly nothing is more creepy than how deep sea anglerfish mate.
The deep sea is dark, and the anglerfish are spread very thinly. Therefore, when an anglerfish meets another anglerfish, it’s incredibly important they get the chance to mate over and over again. The evolutionary strategy that deep sea anglerfish devised is extra creepy. The male latches onto the female, biting her and never letting go. That way he can inseminate the eggs she drops. Not that bad so far right? But wait, how does he eat if he’s latched on his mate?