Doh. Ok, WoG was a bad choice. How about something that just kills all the squirrels? Basically what I was asking was whether all the deaths were put on the stack at the same time, or if I could respond to each one resolving or something.
Goblin Sharpshooter {2R} |Creature -- Goblin| 1/1. Goblin Sharpshooter doesn't untap during your untap step. / Whenever a creature is put into a graveyard from play, untap Goblin Sharpshooter. / T: Goblin Sharpshooter deals 1 damage to target creature or player. ONS-R [Vin Leg Ext legal.]
"Deaths" don't go on the stack; it's a bunch of "untap Goblin Sharpshooter" triggers that do. As Khahan said, in the case of Wrath of God, those triggers are still all there, but there is no longer a Goblin Sharpshooter to untap so you can't really do anything.
Now, let's say a player casts Perish rather than Wrath of God.
Perish {2B} |Sorcery| Destroy all green creatures. They can't be regenerated. 6E,TE-U [Vin Leg legal.]
After Perish resolves and all of the squirrel tokens hit the yard, the stack will look like this:
untap Goblin Sharpshooter (triggered by the death of token #100)
untap Goblin Sharpshooter (triggered by the death of token #99)
untap Goblin Sharpshooter (triggered by the death of token #98)
...
untap Goblin Sharpshooter (triggered by the death of token #1)
So what you would do is let "untap Goblin Sharpshooter (triggered by the death of token #100)" resolve and untap Goblin Sharpshooter; after it does, each player will again gain priority, giving you an opportunity to tap Goblin Sharpshooter to deal one damage to your opponent. After that resolves, you can repeat this process for each "untap Goblin Sharpshooter" trigger until your opponent loses the game or all of the triggers have resolved.