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.
Pteropus
The megabats, including flying foxes, have the greatest encephalization quotient (brain size relative to body size) of any bat family at 1.20. 
This value is equivalent to that of domestic dogs.
Flying foxes display behaviors that indicate a reliance on long-term information storage.
Though they have wide-ranging movements and cover thousands of square kilometers annually, they are consistently able to locate the same resource patches and roosts.
They will visit these resource patches consistently in a strategy known as trap-lining.
They can also be conditioned to perform behaviors, such as one study where spectacled flying foxes were trained to pull a lever using juice as a reinforcement.
In a follow-up to the initial study, individuals who had learned to pull the lever to receive juice still did so 3.5 years later.