Question: why is tybalt called the prince of cats?
Answer: Tybalt shares the same name as the character Tibert/Tybalt the "Prince of Cats" in Reynard the Fox, a point of both mockery and compliment to him in the play. Mercutio repeatedly calls Tybalt "Prince of Cats" referring to Tybalt's expertise with the sword, as he is agile and fast, but also it is an insult.