Final answer:
Mercutio marks Tybalt as a meticulous and technical fencer who is more concerned with style than substance, mockingly referring to him as 'the Prince of Cats'.
Step-by-step explanation:
In Romeo and Juliet, Mercutio describes Tybalt as being precise and meticulous in his fencing abilities, employing a style that is highly technical and fashionable. He mockingly refers to Tybalt as 'the Prince of Cats' and criticizes his adherence to the formal rules of fencing. Mercutio implies that Tybalt is somewhat of a show-off, more concerned with style than substance. This characterization is important within the play as it sets the stage for the fiery temperaments and ensuing conflict between the characters.