Another wiki article on
venomous mammals.
My vote goes to the Platypus too. I wouldn't be going too hard on John though as there are still some who want to argue about the monotremes. I used to fancy that they are a left over mammal like reptile. Whilst I have heard some argue that they are retro marsupials. Either way they are classed as a mammal now. What do our classifications really mean though? Some, for instance, argue that bats are primates. Apparently the immune system of a platypus is 'primitive in that it is derved from it's venom. And this venom may help us produce the next generation of antibiotics for our use.