How is Mercutio presented in Shakespeare's play, Romeo and Juliet?

Mercuito is a very entertaining character. He is full of puns, ribald sexual allusions, and florid speeches like his famous "Queen Mab" speech. He is clever, witty and serves as a sort of foil for Romeo, who, at least before meeting Juliet, is morose and lovelorn. Mercutio mocks Romeo as he pines away for Rosaline, and it is clear that he is only really interested in physical love, not the kind of emotional, romantic love that characterizes Romeo. He is completely oblivious, as are most of the characters, to Romeo's love for Juliet. Mercutio is also impulsive and hot-blooded. When Tybalt comes searching for Romeo, Mercutio, despite having spoken at lengths about Tybalt's skill with a rapier, challenges him to a duel, deliberately provoking him when Tybalt tries to get out of it. And, of course, it is his death that leads Romeo to kill Tybalt.