i would tho advise against rotating pixels! proper (purist if you want) pixelart should not rotate, as that would break the visual grid, which is, well, UNACCEPTABLE.
your original lion is beautifully drawn, but its movement its a bit... horsish, or harish... see the way the arse bumps up on the third frame, or the forepaws on the second... lions don't really move like that.
i think you designed the frames to go like this (i'm going zero-based now): 0-1-2, as it loops smoothly like that, but think also you can do "ping-pong", which would be "0-1-0-2". I find pingpong better for looping animations like walk or run cycles.
Spriter is indeed the last big thing on sprite animation, but for oldschool pixelart i stick to oldschool technologies. CharacterMakerPro is a cool freeware pixelart editor, very easy to use too. 256 colours max. comme il faut.