Tomba is the one and only annoying fat applicant with a square nose. He has already done 34 (he's on his 35th as we speak) attempts on becoming a hunter but is always ill-fated enough to do so. What he does in every year he joins the exam is to eradicate newcomers by any menace means just to lessen the number of applicants as early as possible (as if he's an examiner). But Tomba is yet very unlucky for the newcomers in Batch 287 (Gon's batch) are not that easy to "bring down."
Ponzu is one of the few female Hunter applicants. She is very cooperative and brave. Why? Well, in the part on the exam where two applicants should sleep at one room, she wasn't stunned that her roommate was Borbon - the applicant who loves snakes! (Ummh... okay gotta tell you this. Hisoka was supposedly her roommate but she dislikes him and so he exchanged rooms with Tomba and as a result he ended up with Borbon. She's still brave you know. How could you possibly sleep well if there are snakes slithering around your room?!)
Ponzu is a girl of talent. She knows a lot of things especially on chemicals. In the Hunting Down part of the exam, Borbon became her target and she used bees to unintentionally kill him. The bees are secretly hidden in her hat and goes out instantaneously whenever she screams. The insects then attack the person nearest to Ponzu for they recognize him/her as the reason of their master's terror.
Sniper is the second girl applicant that was introduced in the series. I didn't see her from the earlier exams though. She first appears in the test where the applicants were isolated in an island full of wrecked ships. Sniper played an important role in that part being an expert in gun-shooting. Pitifully, he was killed by his target Gitara Kuro in the fourth part of the exam.
Borbon is the applicant who brings with himself probably hundreds and thousands of not-so-poisonous snakes. Where can he possibly hide them through the entire test? Probably he's one of those geeks who play flute to attract and make snakes move in a peculiar way (obviously).
Borbon's snakes are also pretty handy for only him and no one else but him can control them. Once, he hid in a cave and set the snakes as a trap. Once someone enters that cave, he/she can no longer get out after stepping a foot in the clearing inside the cave for the snakes immediately blocks the way out. Even though they're not very poisonous, one will die in no time because of their number. This thing actually happened to Ponzu, the applicant who tracked Borbon in the Hunting Down part of the exam.
Podoru is the oldest aspirant to reach the last part of the exam. Maybe he trained very hard after last year's exam where he was eliminated right away in the first test. Podoru appears tough and it is obvious in his face and physique that he's a fighter.
Podoru, in his battle with Hisoka in the Last Test, was pathetically defeated by just one hit of Hisoka's index finger on his nose. He needed time to recover after his defeat and so Leorio (his next opponent) gave him the opportunity. When he was already in condition to fight, Killua absentmindedly killed him. Thus, Killua was disqualified. (For a full detail on why Killua did that, check Gitara Kuro's profile.)
Hanzo is the second strongest applicant in the Hunter Exam who doesn't use Nen (Killua is the first). The reason is probably because he's a ninja and ninjas are among the best fighters in the world. Each night they run two mountains or so and they are also taught to carry their weights with their finger/s. Ninjas are taught to fight since childhood so it is not surprising that Hanzo is a good fighter.
Hanzo, even though trained to kill in battles, has a good heart. In his fight with Gon in the final exam, Gon won't surrender no matter how hard Hanzo tortures and injures him. He (also the others) was delighted by the kid's answer on why he won't give up [Gon: "I won't surrender because this is my fight but I also don't want to have many wounds."]. Hanzo had no other choice in the end but to give up and wait for his next fight to begin.
Pokero is a young applicant who also passed the Hunter Exam. On the test the year before, he failed on the fourth test (at least he reached that far unlike Podoru). Pokero is truly not equipped with fighting ability but he uses his brain well. He knows a lot on electronic devices such as radios.
Pokero shows his ability in thinking logically when he darted his target in the Fourth Test with his bow and arrow. He wasn't good enough at aiming for he only hit the edge of his victim's arm. The target at once scrambled into Pokero's direction and then tried to kill him. But the aggressor halted as he was about to slash Pokero. It was because the arrow used was dipped in a poison before being shot. And so, he completed the six points required in no time.
Gitara Kuro is a robot-like character in the Hunter Exam. He looks an idiot with all the needles planted on his face. The funny thing is, he isn't really a robot material. In fact, he is Killua's older brother and is a friend of Hisoka (dunno how).
Gitara Kuro is the name used by Irumi Zordick to disguise himself. He was sent by his mother in order to monitor his younger brother. He reveals his true identity when he was about to fight Killua in the Tournament Test. Killua was stunned and was unable to move and fight. Irumi told Killua that he shouldn't have any friends for he is born an assassin. He even told Killua that he'll assassinate Gon to make it sure that he'll stop growing a heart (But of course it was a lie. Hisoka doesn't want Gon killed you know.). Irumi also told his brother that he shouldn't fight him for some reasons. When he reached a hand, Killua surrendered. After that, Killua started daydreaming - as if asking questions about his life and profession. The next battle was between Podoru and Leorio. It was the time when Killua was disqualified for he inattentively killed Podoru (lucky it wasn't Leorio).
Gereta was once rescued by Gon in the Island of Lost Ships when he tried to leave the island while the first calamity struck. The base of his stick contains paralyzing needles that can be pinned like a bullet.
Gereta's target in the Hunting Down was Gon. When Gon ran away after getting Hisoka's number, Gereta ambushed him and took his and Hisoka's number. A moment later, Hisoka appeared and returned the two number plates Gereta stole. He doesn't need his number anymore for Gereta was his target and he was able to gather three points (from non-targets) earlier.
So to sum it up: Gereta' target was Gon; Gon's target was Hisoka; Hisoka's target was Gereta.
Amori, Umori and Imori are the only sibling applicants in the Hunter Exam (well maybe except for Killua and Irumi). They are fairly similar with each other in appearance for they have horizontal black lines in their eyes similar to those of a clown.
Imori (I'm not really sure) was Killua's target in the Fourth Test. When Killua tried to get his target's number, the other two brothers came to the rescue. Killua is far more skillful than the other three so he had his number in no time. He also stole the number plates of Amori and Umori but instead of keeping it, threw it away in opposite directions.