I really hope this isn't another "idea that all new designers have that quickly gets shoot down."

If Throat Wolf ever got made, it would have to have this ability.

The basic concept is similar to triple strike or what I like to call final strike (a third combat damage step after regular damage), and it is indeed something most amateur Magic designers come up with at over point or another. In fact, TheLonesomeWarrior just tried it out over on ((C41472)).
The issue that's often brought up is that adding another combat damage step is a hassle for the rules. I don't think it's that bad, but it's probably not something very worth doing for a tiny handful of cards, and it's certainly not worth doing for one card. After all, the more sensible version generally involved the third combat damage step coming after the regular combat damage step, which is a drawback by itself and is really only useful as part of triple strike. Double strike is powerful enough that I don't think we need yet another better version.
As a single card, this would be better done as a trigger upon being blocked. That makes a lot less work for the rules.

The idea of a "delayed strike" is also an interesting idea, and would work beter within the rules. I doubt WOTC would ever make it happen, though, since creatures rarely have drawbacks these days.

Is there any way to delete a card in this set, or do I just have to move it?