Possums are practically immune to poison. Almost any poison. And they can make mice immune, too.
Obviously, you can’t just transfuse yourself with possum blood, because A) there are a lot of rabid possums out there and B) possums probably don’t share your bloodtype so you’d die. But since we’re having trouble making antivenin in this country for a lot of snakes (since the one guy who made a lot of it retired), it seems like a good thing for hospitals to learn how to extract the antitoxin factor and keep it around.
Bible Trivia! Why is a New World animal like the possum in the Vulgate Bible?
Actually, while the other is true, but the first likely isn’t. Possums are, for the most part, immune to rabies. Only one in 800 are infected with the virus, and eight times less likely to carry the virus than wild dogs.