Penis
Domestic cats have barbed penises, with about 120–150 one millimeter long backwards-pointing spines. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which is a trigger for ovulation. Lions also have barbed penises. Male felids urinate backwards by curving the tip of the glans penis backward. When male cheetahs urine-mark their territories, they stand one meter away from a tree or rock surface with the tail raised, pointing the penis either horizontally backward or 60° upward.
Dragons (Dragon Prince)
In 719 Feylin had the opportunity to dissect a dragonsire. Sioned and Maarken aided her study using their Sunrunner memory and Maarken also drew careful renderings of bone, organs, and muscles. The dissection revealed that a dragon's brain is about double the size of a human one, but without as many wrinkles. The back portion of the brain is significantly larger than the front portion and the whole thing is a grayish color. Eyes, tongue, teeth, nasal cavity, stomach, lungs, heart, chest cavity, wings, and legs were also all cataloged, measured, and drawn.