Hunter x Hunter, Vol. 4 by Yoshihiro Togashi

[Viz] Plucky Gon’s quest to find his dad leads him into a whole world of crazy adventure. Hunters are a special breed, dedicated to tracking down treasures, magical beasts, and even other people. But such pursuits require a license, and less than one in a hundred thousand can pass the grueling qualification exam. Those who do pass gain access to restricted areas, amazing stores of information, and the right to call themselves Hunters. The fourth exam rages on as the Hunter hopefuls try to gain points by stealing each other's badges. Gon, Kurapika, and Leorio fall into a trap set for another applicant and must face a pit full of poisonous snakes. When Leorio is bitten, Gon braves the snakes to snatch the antidote and a badge! Finally, the friends reach the end of the exams and the ultimate "reverse tournament"--the winner of each round automatically passes the Hunter exam, but the defeated keep competing against each other until the last candidate standing fails the exam. K