For example, the chickens can fly a little bit up in the air and float or glide. For example, the Fresh Animations texture pack has changed the way most four and two-legged mobs walk, stand, run, and swim. The changes on most of the mobs are pretty minor, but it’s the little details that matter. This pack affects friendly, passive, and hostile mobs.
The Fresh Animations Minecraft resource pack mostly focuses on how the mobs look and act.
Fresh Animations Resource Pack: New Mob Movements