The poem is about a mysterious cat named Macavity who is described as a master criminal. He is able to avoid arrest for his crimes as he is never found at the scene of crimes investigated by Scotland Yard. He is seen as the most deceitful and evasive cat who always has excuses prepared and is able to defy authorities through his cunning nature and skills of misdirection. The poem compares him to a snake for his sly movements and presents him as the leader and controller of other criminal cats.