Two resolutions, two different styles.
This is 16×16 pixels, the movement captured in less then 6 frames. I read somewhere, that an animated, live object needs to me moving almost all the time, even in small details, to look good and, well, alive.
That is 32×32: a little bit more detail allowed. I really had fun with the spooked, growling dog: the simple three additional pixels on his back really makes the appearance of fur bristling on its back.