The Chaucer Review: An Indexed Bibliography (Vols. 1-30)

Benson, C. David. "Their Telling Difference: Chaucer the Pilgrim and His Two Contrasting Tales." 18 (1983): 61-76.
Chaucer does not give enough information about the pilgrim identified with himself in the Canterbury Tales for critics to claim that the pilgrim is a well-developed character. The tales this pilgrim tells, however, present a dramatic contrast between clever and poor art. The Tale of Sir Thopas is not satiric, but a highly imaginative, carefree tale of nothing. The Tale of Melibee is the stylistic opposite of Thopas. Melibee is highly moral and has little imaginative content either in words or ideas. Chaucer does not merely contrast good with bad art, but different ways to use language. Thus Thopas and Melibee work best when read as a unit.

Haskell, Ann S. "Sir Thopas: The Puppet's Puppet." 9 (1975): 253-61.
Sir Thopas is a joke figure, the puppet of Chaucer the pilgrim, controlled by Chaucer the writer. Details in the description of Sir Thopas indicate that he may have physically been a puppet. Ultimately, the character of Thopas, however artificial he may be, is real.