Hyena females are not only bigger and more aggressive then the males, but they have pseudo penis. This makes them more difficult to mate as well makes giving birth to their young a painful and dangerous exercise as the offspring has to pass through the pseudo penis.
The temperature of the water the tadpoles live in determines the sex of many amphibian species.
Wolves pair for life, with only the leader pair in a pack breeding. This is so they do not out breed their food source.
In some species of snake, the male has two penises. In some species, the snake gives birth to live young, unlike the more common laying of eggs.
Some marsupials can postpone the development of a fertilised foetus if there is a drought or other stress until the conditions are more beneficial.
In some large carnivore animals, such as the tiger or polar bear, the mother has to protect the young from their own father, because he will try and eat them.
In some shark species, the females give birth to live young, and the young eat each other in the womb. Only the most aggressive baby sharks make it out.
Coral reefs spawn on the same full moon every year. The eggs can be seen from the air as a giant pinkish current. Many of the oceanic animals gather at that that time and place to feed on the spawn and each other .
Male cats, large/small wild/tame, have all got spurs on their penises so as to wound the female so they are less likely to have sex with another male and thus ensure a greater chance of his genes being passed on.
Worms, slugs and snails are hermaphrodites. They have both male and female organs and can, and do, preform both roles. During mating periods, they often become brightly coloured and are very beautiful. Snails shoot arrows of sperm through each others flesh to impregnate the female organs.
Homosexuality is found in the natural world. Dolphins are known to pair as male companions, with breeding females coming for mating and then leaving. Rats and other rodents will mount other males.
Plants have beautiful and easily seen flower petals all though they cannot see them themselves. The point of the petal in reproduction is to make a landing pad for flying insects (or small animals) to land on to get the nectar and spread the pollen. The petals have ultraviolet lines and marking that act as guides for the insects which are able to see them.
All these things makes one suspect that anything responsible for creating the living world likes food, is indulgent, loves diversity, is artistic, understands mathematics practically and purely, is both nurturing and ruthlessly protective, has an raw edge, has a sense of humour, is brilliant, and might be a little bit... offbeat.