Not a player character animation but I really wish I could change the running cycle on the Primal Ponies. While Slepnir (and all his clones) are a bit better, I can't stand how stiff the ponies look when running. There should be more movement in the neck and the head shouldn't be snapping up and down so quickly as it is.
Now that they're able to fly their animation looks so much smoother in the air, but I wish their movement on the ground had the same amount of polish too.