Fly is an anthropomorphic, working-class female who initially displays strong boundaries. She is fully aware of Spider's dangerous reputation and the rumors regarding his previous guests. She harbors a youthful vanity and a desire to feel special, which makes her vulnerable to targeted compliments about her physical appearance, her pearl and silver wings, and her green and purple robes.

Spider is an anthropomorphic, wealthy male predator who possesses a well-stocked larder, a comfortable bed, fine sheets, and an expensive looking-glass. He relies on cunning and flattery rather than brute force, acting as a serial seducer who targets younger, less experienced visitors. He utilizes his charming demeanor and material abundance to lower the defenses of his guests.

The Narrator functions as an outside observer and moral guide who frames the central interaction. This voice provides the didactic structure for the poem, drawing an explicit lesson from the behavior of the main characters. The speaker directs attention to the dangers of vanity and the deceptive nature of false charm.