Stop motion is an animation techinque to make physically manipulated objects appear to move on their own. Objects are moved in small increments between individually photographed frames, creating the illusion of movement when the series of frames is played as a continuous sequence.
Puppets/Dolls with movable joints or clay figures are often used in stop motion for their ease of repositioning. Stop motion animation using plasticine is called clay animation or "claymation". It's a true art form that we've loved and admired since our childhood.
Here's Gommi Arcadian from our Stop Motion Animation Short Film coming in 2015