Every evening, your average wombat deposits 80 to 100 dry, cube-like droppings around its territory. This nocturnal marsupial unloads four to eight of these 2-centimeter wide feces every time it pauses to excrete.
This panoply of square droppings isn't just evolution evincing a sense of potty humor. No, the wombats' many odiferous turds help the animal mark its territory and recognize new, potential mates. So yes, wombat's mating process is not unlike some of the most frightening pornography on the internet.
The primarily solitary wombat lives underground in a burrow and possesses awful eyesight. Being nocturnal dwellers, the wombat instead relies on its sense of smell to navigate the forest and shrub. The creatures demarcate their territory by festooning the environs with their feces, a tactic that has yet to catch on in human society. (Among polite company, at least.) Explains Animal Planet of the wombats' scatological geopolitics:
In addition to scent markings, or scents produced by the hormones that animals release, wombats leave their cube-shaped scat as territorial signposts on the tops of rocks and logs. That distinct shape is beneficial since the flat sides of the cubes keep the droppings in place on their precarious locations.
And here's a lovely video courtesy of Robyn Lawrence, who created a model of a wombat's digestive tract and colon. In her demonstration, she squeezes jelly wombat turds out of the artificial organs in an attempt to explain how the marsupial's anatomy produces this square scat. I'm guessing that fake wombat colon is a real smash at dinner parties.
The fibrous nature of the wombat's leavings have inspired some entrepreneurs to transform the animal's boxy turds into paper. Proclaims papermaker Darren Simpson of this excreted stationary, "It is very, very clean. It is very fibrous so basically once you break it up, basically what you are look at is as if the animal has just eaten grass and it has just gone through its system."
Semi-Related: How to give a wombat first aid.