He reminds them that the Prince has forbidden street-fighting.
SPOILERS Romeo, Juliet, Tybalt, Paris, and Mercutio.
Romeo mercutio tybalt Juliet
[You meant ''Who is Tybalt?''] Tybalt was Juliet's cousin. He is a Capulet. He kills Mercutio and soon dies by Romeo. Then Juliet gets mad at Romeo for killing her cousin (The Nurse tells Juliet that Romeo killed Tybalt). Soon Juliet forgives him because she cares more about Romeo banish (He got banish because he killed Tybalt, Friar Lawrence gives him this news) than Tybalt's death.
Tybalt was killed by Romeo, who was angry at Tybalt for killing Mercutio.
Juliet, Romeo, Tybalt, Nurse, Benvolio Or . . . Juliet, Romeo, Friar Lawrence, Nurse, Capulet Or . . . Juliet, Romeo, Friar Lawrence, Capulet, Tybalt Or . . . Juliet, Romeo, Capulet, Mercutio, Tybalt Or basically Romeo and Juliet and any three of Nurse, Friar, Capulet, Mercutio, or Tybalt.
Mercutio calls Tybalt a coward in Romeo and Juliet.
Tybalt
In the play "Romeo and Juliet," Mercutio is killed by Tybalt in a sword fight. Tybalt, seeking revenge, challenges Romeo to a duel. Mercutio steps in to defend Romeo, but Tybalt fatally wounds him under Romeo's arm.
When Romeo killed Tybalt after Tybalt killed Mercutio
Tybalt Killed Mercutio and then Romeo was so cross he decided to kill Tybalt! =) x
earlier in the play, romeo crashed a Capulet party. angry, Tybalt swore revenge with a sword fight. Romeo's friend mercutio ends up fighting Tybalt, and romeo attempts to intervene by stepping between them. Tybalt stabs mercutio, despite Romeos attempts to end the fight, and mercutio dies. Romeo and Tybalt then fight, and romeo kills Tybalt, and romeo is banished from Vienna. Merutio, romeo and Tybalt sword fight.
Mercutio was killed when Tybalt stabbed him in the begging of Romeo and Juliet.