Biondello finds this merchant to dress up as Lucentio's father Vincentio. Tranio tells the merchant, who is from Mantua, that the duke of Padua has ordered for the death of any Mantuans found in Padua, because of a dispute between the two cities. Tranio convinces him to pretend to be Vincentio, supposedly in order to save his life (but really in order to convince Baptista that Lucentio is a suitable husband for Bianca).
The timeline below shows where the character Merchant appears in The Taming of the Shrew. The colored dots and icons indicate which themes are associated with that appearance.
Act 4, Scene 2
Act 4, Scene 4
Act 5, Scene 1
...with Katherine, Vincentio, and Grumio. Vincentio knocks on the door and asks for Lucentio. The merchant (who is impersonating Vincentio) tells him Lucentio is busy. Petruchio says that Vincentio is Lucentio's... (full context)
...but Biondello pretends not to know Vincentio. Vincentio angrily beats Biondello, causing Biondello and the merchant to cry out that a madman is attacking them. Biondello leaves. Baptista and Tranio (still... (full context)
Act 5, Scene 2
It is finally time for Lucentio and Bianca's wedding banquet. Baptista, Vincentio, Gremio, the merchant who had pretended to be Vincentio, Lucentio, Bianca, Petruchio, and Katherine are all present. The... (full context)