Tybalt is very dedicated to the feud that exists between the Capulets and Montagues. He does not want the Montagues to have the upper hand in the feud, and wants them to pay for any action Tybalt sees as a wrongdoing.
The first time that Tybalt appears in the play he immediately joins the brawl despite Benvolio’s pleas for Tybalt to help break up the fight and restore peace. As Tybalt says, “I hate [peace], / As I hate hell, all Montagues, and thee.”
When Tybalt next appears in Act I, scene v he again wants to start a fight, this time with Romeo, after realizing that Romeo and his friends have crashed the Capulet party. It is only Lord Capulet’s warning not to start anything and to back off that keeps Tybalt from acting on his desires. Lord Capulet does not seem bothered by the fact that Romeo is at the party, and even compliments Romeo saying, “Verona brags of him / To be a virtuous and well-govern’d youth.” Romeo has done nothing to invoke this much of Tybalt’s wrath, further emphasizing Tybalt’s rashness and hot-headed actions. Before Tybalt leaves he promises that Romeo will pay for what he has done, ominously hinting at what is to come.
The final scene with Tybalt, Act III, scene i, again exemplifies his quickness to anger as he tries to goad Romeo into a duel. Tybalt has taken “the injuries / That thou hast done me” (Romeo attending a party he was not invited to) to the extreme if Tybalt wants to fight Romeo to the death. It is assumed by all (Mercutio and Benvolio included) that Romeo will participate in the fight, but Romeo is in love, has just married Juliet, and does not want to fight someone who has now become his relative. Tybalt will not take no for an answer and is himself goaded into fighting Mercutio. Even after he has killed Mercutio, Tybalt returns to the scene of the crime and fights Romeo, perishing in the end. It is these brash actions and single minded focus on the Capulet/Montague feud that lead to Tybalt’s death.