Final answer:
The theme of 'Macavity the Mystery Cat' is the elusiveness and cunning of the main character, Macavity, supported by evidence from the poem.
Step-by-step explanation:
The theme of "Macavity the Mystery Cat" is the elusiveness and cunning of the main character, Macavity. This is supported by evidence from the poem such as Macavity's ability to disappear when he wants to, leaving only his paw prints behind. Another piece of evidence is the line "Macavity's not there!" which emphasizes his mysterious and elusive nature. Throughout the poem, Macavity's actions prove that he is a master at avoiding capture and solving crimes, making his theme centered around his mysterious and elusive nature.