Step 1: Understanding the Concept:
This question tests your understanding of the poetic device used in the last two lines, which describe the chameleon's special ability.
Step 2: Detailed Explanation:
The last two lines of the extract are:
"If there is nothing on the tree,
'Tis the chameleon you see."
This is a paradox. The poet is humorously explaining the chameleon's ability to camouflage itself perfectly with its surroundings. When it is on a tree, it changes its color to match the tree, making it seem like there is "nothing" there. Therefore, if you look at a tree and see nothing, it might just be a perfectly camouflaged chameleon.
Step 3: Final Answer:
According to the poem's logic, if you see nothing on the tree, you are actually seeing a chameleon.