Spun off
from here.
And why not allow massive damage as a catch?
Narratively: 1) it simply doesn't make sense for me to have one piece of lead allow regeneration while another doesn't; 2) it's boring - a bigger boom always does more damage; 3) military grade weapons aren't "hide-able" (as in from the law and other mortals) in an urban setting. Mechanically: 1) "massive damage" is poorly defined and, while it could be narrowed down; 2) it will mean near automatic extreme injury or death and consequently; 3) lead to down time or, worse, sitting out scenes for healing. Metagame reasons: 1) going from ping "I'm not hurt" to "Boom I'm dead" isn't usually fun; 2) yet catches above 0 should show up in the game; and 3) the same weapon is likely to completely destroy other team members.
I'm pretty sure I can answer #1 of each category pretty well.
But the others are good points.
Still, I can't think of a better catch for a large animal.
Think about this:
Normal rifles are fairly worthless against an elephant (according to Orwell). But an elephant gun can kill one in one shot. How would that work without using the Catch mechanics?
I honestly don't see the need for large animals to have toughness / recovery powers...much less a catch. A high Endurance, the "No Pain, No Gain" stunt, and the Hulking Size power (when appropriate) should be plenty against any normal animal. Basically, your elephant probably has 6 stress boxes and two extra mild consequences. That's enough to make taking it down with a light weapon extremely difficult.
As for needing a high powered rifle to damage an elephant,
this guy took one down with a bow (don't watch unless you want to see a dead animal). In short,
controlling the situation and accuracy are far more important than weapon power. That last really applies to most situations. It's not hard to damage people or animals. When you're accurate, a .22 will kill a human as dead and as easily as a .50 caliber. I do think FATE's aspect creation rules do a good job of modelling this...better than most games I've played.
Edit: I would also like to see your thoughts on the #1s!