Wombat poop is cube-shaped.
Why it is true
Their intestines stretch differently, forming the waste into cubes so it doesn't roll away, which helps them mark their territory.
Source: Biology Research
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.