After mating, the male garter snake from North America closes up the female's sexual opening with a plug made from kidney secretions. This is a form of chastity belt to ensure that the female is fertilized by the first male to mate with her.

The seahorse is the only creature where the male becomes pregnant. The female inserts a nipple-like appendage into the male and releases her eggs into a special pouch in his stomach. He then discharges his sperm over them and his stomach takes on the rounded shape once the eggs are fertilized.

The female bedbug has no sexual opening, so the male creates his own vagina, using his curved, pointed penis as a drill.
The male then inserts his sperm and the blood-sucking female feeds on some of it when blood is in short supply.

After the female praying mantis mates with her partner, she then eats him. The female hooks her deadly arms around him and slowly nibbles away at him during copulation. Sometimes she doesn't even wait until after sex to make him her next meal, but his sex drive is so strong that he can keep going even while being eaten.

The male swamp antechinus, a mouse-like marsupial from ustralia, is the only mammal which dies after mating. The males dedicate their lives to non-stop mating until they literally drop dead. Most of them die of starvation because they have no time to eat between sex.