The 12 principles of animation number 10#: timing

there are three types of timing :
physical timing: is used to make objects and characters believeable by creating weight, gravity and mass.

theatrical timing: is used for both comical and dramatic effect by the character having a personality it can alter how fast or slow they do actions like walking and running.

musical timing: this isn't exactly connected to the animation but it can help with creating the mood of the character. a good example is Lego Harry Potter 5-7 on DS; as the player gets closer to a enemy the music changes into a more battle-mode that excites the player as they get ready to attack.