What is Justin Bieber's favorite pet?

Explanation

Justin Bieber's favorite things: blue (color), purple (color), 6 (number), shawty (slang word), dog (pet), porcupine (animal), birthday (day), Tuesday (weekday), November (month), afternoon/evening (time a day), Christmas (holiday), Bahamas (vacation), South Beach and Florida (state), English literature (subject in school), Twitter (website).