#burrowing octopus

I am sure you saw this gif somewhere before:

What you may not know is that this is a unique skill of the sand octopus. Other octopuses are known to hide into the sand. However, to still be able to breath, they remain close to the sediment surface, with their funnel sticking out. This one is different.

First, the sand octopus uses its water jets to create quicksand and thus is able to disappear in a matter of seconds, using far less energy. Second, it has a clever way of creating little burrows, so it can really hide away.  

 → link to full resolution image

Burrowing is really unique to this species, and one suspect they developed this skill because, unlike many other octopus species, it lacks camouflage skills.

For sources and more information:

very nice article on newscientist.com