Nobody's written a half-elf yet and there apparently aren't any immediate plans for one, but someone could write one up if they felt like it. There's really no point in making it a TF because you can already give your Champ any mix of traits you please and I'm pretty sure Balak would rather pitch himself off a cliff than try and make the appearance system track the fact that your Champ is 50% human, 26% lupine, 14% cowgirl, 9% siorcanna and 1% mecian. Shit like this is why the system has the 'chimera' option to begin with.
Also, because of your magically recessive genes you'll never have half-anything children so figuring out what offspring of any particular couple would be like just isn't a priority until someone actually sets down to write one.