Extreme Monotreme

They've run through the DNA code for the Platypus.

You know, that comical critter from the land down under.

It's furry and duck-billed and lays leather eggs
and keeps deadly poison in claws on its legs.

Update: it's only the male who has the poison on a spur on each of his back legs, and it's not deadly to humans, just very painful.

Of course, it's only the female who lays eggs, so I could try redoing it like this:

They're furry and duck-billed.
She lays leather eggs.
He has spurs - poison-filled
upon his hind legs.