What is the importance of "toads" in the novel, Hamnet?

The toad symbolizes failure throughout the novel. When Hamnet stumbles upon his grandfather in the workshop, he compares his grandfather's defeated posture to that of a toad. John's fall from social grace and failure to reinstate his reputation are consistent with the toad's symbolism.

The toad next appears as a medical remedy. The physician arrives late in the progression of Judith's illness, offering only a dried toad to be tied around her stomach to repel the plague. Agnes scoffs at the toad, insulted by the prospect of trying to save her dying daughter with an old wives' tale. The toad symbolizes the physician's failure to help Judith when Hamnet first calls for him. The toad also symbolizes Agnes's eventual failure to save Hamnet when her own natural remedies do nothing to stop the plague. Agnes binds the toad to Hamnet's abdomen in desperation when she realizes she is helpless, clinging to an object she knows has no value to try and make up for her failure to save her son.