1.It is nearly impossible to lick your elbow with your tongue.
2.Fatal familial insomnia: a rare genetic disorder in which a patient completely loose its ability to sleep accompanied with severe panic attacks and hallucinations. Ultimately it leads to coma or death.
3.Seahorses:- one of those rare animal groups in which the male gets pregnant and carries the eggs in a pouch.
4.Turritopsis dohrnii also known as immortal jellyfish. They can theoretically reverse their ageing.
5. The blue ringed octopus: A cute small octopus but contains a powerful neurotoxin which paralyses respiratory muscles. And no antivenom exist till now.
But you can be saved if you receive supportive treatment on time.
6. Anglerfish:- some species of these fish reproduce via sexual parasitism. Males are small in size they bite the larger females and become permanently attach to them while taking nourishment from them and supplying sperms.
7. The diving bell spider:- It spends its entire life underwater.
8. Elephant is the only animal that cannot jump.