Birthday: June 6
Horoscope: Gemini
Age: 28
Height: 187 cm
Weight: 91 kg
Hair color: 1999 anime - blue (Hunter Exam arc), red (Heavens Arena arc); red (2011)
Eye color: blue (1999), yellow (2011)
Blood type: B
Occupation: Hunter, Phantom Troupe's #4 (former)
Nen type: Transmutation

Notorious for his cruel and deceitful fighting ability, Hisoka has proven to be deadly. His deviousness and volatility has made many opponents have difficulty anticipating his next move, and this has led to him winning many battles. Using Shu powered poker cards as his primary weapon, he throws them with ease and deadly accuracy.

Also, he is very intrigued by Gon and the potential this young boy has to become an adept and powerful adversary. Hisoka, ever looking for a strong opponent, is willing to aid, or at least not defeat prematurely, someone that could develop into a future opponent.

During the Yorknew City arc, Hisoka is revealed to have recently replaced the fourth member of the Phantom Troupe, though his association with the organization is, rather characteristically, based on his drive to fight remarkable opponents. His main goal was to fight their leader, Chrollo, but his membership proved to be a farce, because he would never appear without other Troupe members, and rarely at that. This information is divulged in secret to Kurapika.
(Source: HunterHunter Wikia, Japanese Wikipedia)