Brilliant idea!
Though, I have to confess that I, too, are wondering what for I could use them... I'm a gamer, not a miniature painter, you know.
Maybe if we had some suitable adversaries, say... ummh... I'm afraid I'm a little disadvantaged concerning the mexican fauna, living in the old world.
Rattlesnakes with sombreros? Could be nice... but how would they hold their guns? Hm... Sir Hiss comes to my mind... do you remember? The snake from the old Disney Robin Hood film? If I remember correctly, he used his tail (can i call this a tail, the end of a snake's body?) if he had to do something else than moving and speeking.