Strepsiades is the anti-hero of Aristophanes's play. He is an older Athenian citizen and a farmer. He married a well-to-do girl with aristocratic pretensions and has a son, Pheidippides, who has inherited the young woman's rarified tastes and has begun running Strepsiades into the ground with debts to finance his stables of expensive horses. Strepsiades is fundamentally dishonest: the action of the play occurs, in fact, because Strepsiades does not wish to pay the money that he owes his creditors. This dishonesty is no mere whim, but it sees Strepsiades through many a painful trial in its pursuit—be it the loss of his coat or the confinement to a flea-ridden bed. A plucky, stubborn fellow, Strepsiades does not loose his resolve once: not when trying to convince his smug son, nor when trying to wrap his stumped brain around some of the school's teachings, not even when Socrates rejects him as a hopeless failure. In this sense, sad Strepsiades represents the Athenian tenacity, especially when one considers that Aristophanes was composing his plays during the interminable Peloponnesian War when Athens and Sparta were at war for decades on end.
Strepsiades is a practical man: he has a problem—he is in debt—and he finds an existing solution for it in the theories and arguments taught at Socrates's school. In spite of the fact that he places his hopes on the slippery rhetoric and shady morals of the new sophistry and "new education," Strepsiades is a countryman and a traditionalist at heart. He wishes that his son Pheidippides were a farmer like him and his father before him. He gets into a fight with Pheidippides when Pheidippides disdains his request to recite some of the traditional poetry of Simonides and Aeschylus, works that made up the backbone of any traditional education.
Strepsiades's practicality manifests itself in his hearty physicality. He is comfortable with his own body and all that it produces. His quickness to violence and his low physical humor suggest this ease in his own skin. Since Strepsiades is a comic anti-hero, his physicality necessarily means that he had no intellect to speak of: when placed by Socrates into the flea-ridden bed to philosophize, Strepsiades masturbates. Likewise, when Socrates speaks of the Chorus of Clouds as "in a whirl" (I.ii.361), Strepsiades thinks that he has discovered a new god called "Awhirl" (I.ii.814). His inability to process subtle (and not-so-subtle) intellectual details makes him a good foil for the pale, ethereal Socrates.
As the play progresses, Strepsiades comes, like a tragic hero, to regret his actions. When he is being physically and verbally assaulted by Pheidippides, newly armed with his fancy sophistic education, Strepsiades bemoans his earlier rashness in considering the "new education" the solution. However "just" he considers the Chorus of Clouds's verdict to be, he still persists in burning down the school and calling it "revenge" (II.i.1506). Therefore, his admission is a half-hearted acceptance of his own accountability at best.