Siam Kid

The leader of "Team Fearless," a group of vampire hunters. Hired to assassinate Staz. He has the ability to change into a cat. Siam Kid is very ambitious, and overestimates Staz' vampiric ability. Despite his eagerness, the rest of his team knows he is not able for the responsibility of the task ahead. Numerous times he is tempted by a drug called "silver vine" that supposedly he habitually used in his past. By having a part of someone's body, like hair, Siam's power allows him to predict the actions of his opponent.

(Source: Blood Lad Wikia)