Very good looking but also very high-poly model. I recommend cutting off some polygons; a few areas I see that could use a bit of poylgon-shaving are the bone 'spines' that come out of his back, his actual spine, and the 'coat' under his 'leaf' things. What I recommend is to either remove the bone spines or redo them somehow with a lot less polies(they are the most high-poly part of the model, or so it seems), make the spine a simple cube or 5-sided cylinder and completely remove the 'coat' thing as it is not visible at all. His leaf-ish things could also use some work, they look rather strange and are sort of high-poly. I suggest making them more like a coat, going down instead of weirdly floating upwards like that. His pelvis bone could also be removed, it is barely visible and will most likely be ignored in-game, especially with those huge leaf-cape things that hide most of his lower body.
Now, for animations: All the attack animations could use some more power. He should strike a little bit faster, and his scythe should go much farther; currently it looks like he stops in the middle of a strike, especially on Attack - 2. Attack - 3 makes no sense; you don't use a scythe like that! It seems very weak. Attack Slam looks great though.
Death makes absolutely no sense to me; why would he rip off his own heart and smash it? I suggest, instead, making his 'heart' crystal fall off while he himself is falling, and as the crystal breaks and disappears to dust the skeleton darkens and becomes dust as well. Perhaps leaving only his clothing and scythe that will rise in Dissipate.
In many animations, like Spell, Spell Channel and Stand - 3, the skeleton's hand goes straight through his leaf-cloak and sometimes even through his skeletal spines on the back. This is minor, but looks rather strange.
Walk is very slow - I suggest adding a 'Walk Fast' animation where he is actually running, to fit more with the rest of the Warcraft 3 units.
Other than that, I've got nothing to say about the animations. They are all great - very creative at times, and very fluid as well. They work well and make sense, mostly. I like stand channel, except for the whole 'hand goes through cloak' thing that I mentioned. Perhaps consider removing the leaf-cloak instead? More of the model's details will then be seen in-game, making many of my previous statements unneeded.
Now, to game mechanics: You've got most of it - death sound, footprints, collision object, etc. What you seem to lack, however, is teamcolor and teamglow. As it is a hero, teamglow is required to distinguish it in-game. I highly advise you to implement teamcolor as well.
Other than what I mentioned, it is a very nice model. It's creative and very nice, and doesn't abuse the Skeleton head texture\mesh... Despite being skeletal. Great job!
Approved
