What happens if a predator eats a platypus?

Platypuses do not have teeth; nor do they bite. The only danger posed by a platypus is if it "spurs" a person by the male using its venomous spur on its hind leg to pierce someone's skin.

Male platypuses have a venomous spur on each of their hind legs, through which they can deliver a venom strong enough to kill a small dog, and to cause almost paralysing agony to an adult human. Also, platypus venom contains a protein which lowers blood pressure, also inducing shock. People who have been "spurred" by a platypus report that the pain is strong enough to cause vomiting that may last for days, weeks or sometimes even months. The pain cannot be relieved by morphine and other standard pain-killing drugs. It seems the only way it can be relieved is through anaesthesia of the main nerve from the spur site.