This actually isn't meant to be an Anthro pokemon, but is in fact a Cofagrigius so ancient and powerful that she has started to regain her humanity. Though spiteful of her fate like most of her kind, She wasn't satisfied to remain a pokemon and has instead been gathering power and human essence (taken from those who invade her tomb) to try to become human again.

While she has regained enough of her humanity to assume a tangible human form and be unaffected by Pokeballs, she still hungers and has strong instincts like a Pokemon and is unable to speak anything other than Pokenese despite her best efforts, a REAL sore spot for her. It's bad if she is angry at you, but if she instead tries to talk to you and all that comes out is "Cofa Cofaa~", you might be in even MORE trouble. It's possible that the stain on her soul caused by draining the life-force from several humans will keep her from fully attaining humanity, forcing her to experience this agonizing not-quite-human, not-quite-Pokemon form for eternity. Due to this form, she is too ashamed to leave her tomb or seek out another method as she worries she will be treated like a monster.

Her form is slow and shambling, but her shadow hands are quick and long-reaching thanks to how powerful she has become, so escape is difficult.

Ya know what? I think Deoxygirl just got a villain.