While the above scenario -- getting distracted during a cat fight and allowing a Tonbonga, which is a type of a walking tree monster, to sneak up on you, grab you and chuck you into a pit of quicksand -- isn't likely to happen unless you're on a Pacific atoll downwind from an A-Bomb test, quicksand can still pose a problem for the unwary.
Quicksand is formed when sand particles become super-saturated with water. It appears to be solid, but when stepped in, or when thrown in by a Tobonga, you'll start to sink into it. Unless you struggle like the woman in the clip above, you shouldn't sink below the surface because quicksand is denser than the human body.
You escape by wiggling your legs to free them, laying upon it to spread out your surface area to float upon it and, so to speak, swim out of the pit. A French guide demonstrates how to escape quicksand in the video clip below. The important thing is to not panic when you first get stuck in it, just slowly work your way out of it.
By the way, the top clip is from the 1950s sci-fi masterpiece, From Hell it Came. To escape a Tobonga just saunter away from it while trying not to double over in laughter. To put it mildly, they aint the fastest movie monsters ever filmed.