Something about the ability doesn't make sense: it says during the opponents untap step, either pay (2/b)(2/b) or 2 life for each each creature to untap. The thing I see this as (ver batum) is that the opponent does not do this, but this cards owner does: meaning the opponent may never have any creatures untapped because why would "Kit Foxcat"s controller want the opponents creatures to untap to begin with? You may need to edit the card to where it says: "During your opponents untap step, they must pay (2/b)(2/b) or two life, otherwise their creatures do not untap."

This card just seems unfair being that, sense it does not state the opponents pay the cost, it grants that ability solely to it's controller.

i forgot one word... but it's fixed now

That's okay, I am glad I could bring that to your attention. :)

As it stands, you are correct saying that it is a fun, but very devious card. ^_^