the guy in the grass with the gun. Twelve-bore.
I sank through the floor of the earth
to swim in the sea.
Mermaid, me, big fish, eel, dolphin,
whale, the ocean's opera singer.
Over the waves the fisherman came
with his hook and his line and his sinker.
I changed my tune
to racoon, skunk, stoat,
to weasel, ferret, bat, mink, rat.
The taxidermist sharpened his knives.
I smelled the stink of formaldehyde.
Stuff that.
I was wind, I was gas,
I was all hot air, trailed
clouds for hair.
Carol Ann Duffy, of course, ends humorously with a  pun . ‘Stuff that’ is a colloquial expression to convey contempt or disgust. It is also what the taxidermist, literally, does. Again, Thetis has used her wits and escaped.
Thetis