Video prompt: A family of otters playing energetically at a riverbank, sliding down muddy slopes and diving into the water with playful squeals.
Defect: Deformation (when Object is involved in an act,  anything in this process that's weird. e.g. people walk into a wall. "Walk" is an act)
Explanation: The tails and mouths of the two otters, along with the areas where the tails connect to their bodies, undergo unnatural changes in length and shape as they move, creating an unrealistic effect.