Finally, how do you handle an echidna?
Answer: very carefully! If you do ever need to handle one (I once stopped traffic on the Hume Highway to move one off the road, so this sort of situation can arise*), either use heavy leather gardening gloves, or an old coat, or several layers of thick towelling. At a pinch, two wallets will save your hands...
We cannot call any of these organisms, or their outer layers, pointless.
* I have to say that the Hume Highway drivers I briefly inconvenienced were all considerate and understanding.