Follow through and overlapping action; and why it matters to you.
The basic idea to this form of animation is that while a "main mass", like a body, stops moving its appendages will not immediately cease in movement where they would gradually come to a halt. This is a big aspect for it again, gives life to a piece.

So what the heck is this block on a string?
Well the string is supposed to simulate the movement of the body and the delay that other parts of it would have in the process of coming to a stop. See that little curve of the tail there in the photo? That's the product of me wiggling it around and taking as quick a shot as possible.
Anyway, basically this operation would work similar to the movement of a cat's tail.
Kitty tale wiggle for example!

So what the heckle deckle type of magic did I perform to have this effect?
Here's how the legend goes:
YE WHO GOETH INTO THE TIPPIEST TOP OF THE LEFT HAND CORNER OF THY'S SCREEN SHALL FIND THE DYNAMIC MODULE AND PROCURE A SERIES OF OPTION. THEE WHO CHOOSETH THE CHOICIEST OPTION (DYNAMIC NOT ANIMATION) OR PRESS THE BUTTON F5 TO GET THE SAME EFFECT. THEN YE SHALL FIND THE "SOLVERS" OPTION AND CHOOSE INTERACTIVE PLAYBACK!
ONCE THESE QUESTS ARE FULFILLED AND THE BRAVE HEART PRESSES PLAY MAY YE FIND THE ABILITY TO WIGGLE THINE YARN!
IN THE MOMENT OF A CHOICE WIGGLE (WHICH I FAILED TO REMEMBER) YE MAY BE ABLE TO HIT THE ESCAPE KEY AND FULFILL THINE AESTHETIC SENSES WITH THE PLEASURABLE PICTURE OF A STRING BEING SHAKEN INTO A CURVE.