This isn't an official minigame, but it seems to be pretty entertaining. Head out to the countryside and start bombing down the little two-lane desert roads all over the place. You're bound to hit SOMETHING. In the first 20 minutes of controlling Trevor I think I hit 3-4 coyotes and a deer.
XBL Gamertag: JWRebholz
PSN ID: jwrebholz
...No, I'm not very creative when it comes to this sort of thing.