It's the house guest that no-one wants to have over for dinner.
When a woman in Brazil returned to her house after the recent floods that hit the country, she pulled back the sofa to reveal a very snappy visitor.
It was a metre-and-a-half long alligator - and what was worse was her 3 year-old-son was giving it a stroke!
Luckily, the 'gator was in a good mood, so the woman grabbed her son and left the house - and firemen took the toothy fella to a local animal centre.
Alligator (top) and Crocodile (bottom)
So, a quick test then Newsrounders: what's the difference between a crocodile and an alligator?
If you didn't know - they are quite similar... but....
>> Crocs are usually a lighter olive colour - alligators are sort of blackish.
>> Crocs have narrow V-shaped snouts while an alligator's is wide and U-shaped.
>> Alligators prefer freshwater life in rivers, but a croc would much rather be in saltier water near the sea.
>> When a crocodile's jaw is closed its teeth stick out a bit - another difference from the alligator.
So now you know!