Yeah you could make the mod yourself if you wanted to wouldnt be that hard.
I very much doubt it will be that easy. If the Spriggans are the same as in previous TES games, they're 'creatures', meaning they are a separate mesh with their own skeleton and set of animations. It's not a simple matter of ticking some kind of 'playable race' check in the CK like what you would have if you made a new race by using meshes used by the current playable races.
I'm not a real modder myself but I've been following the mod community since Morrowind and this is based on what I saw people do in MW/OB when they asked for a playable creature. My guess is, the closest you would get is by doing it the 'werewolf' way. The werewolf is a creature mesh 'pasted' over your character which is rendered invisible (I think) but as you probably know, the werewolf is very limited as in it can't wear armor, use weapons, talk to people, use containers etc etc. With some decent scripting you could probably make it so that you're able to talk to people while playing a Spriggan, but you most likely will not be able to use weapons or wear any kind of clothes or armor because they would all need to be remodelled to fit the Spriggan mesh (and why would they wear clothes anyway?). It would probably also require new animations because as far as I know, Spriggans have no sprint or sneak animation, or animations for holding and using weapons. I've never seen them jump either.
Again, this is just a guess. My modding knowledge only goes as far as placing an item ingame, building a simple house and adding a new race with existing race meshes. Perhaps playable Spriggans will be easier to do in Skyrim then in previous games but I really doubt it.