
Within the canon of the series, he is shown to be a highly skilled individual - he is extremely mobile especially for someone of his size, has a vast knowledge of how to kill almost any humanoid in a variety of ways, is a survivalist, and is extremely hard to contain. He is also a dangerous convict and murderer - yet despite this, he is sometimes shown to perform moral or even atypically heroic actions, usually against his better judgement. Riddick is one of the last of his kind. One of his most defining features are his eyes which have been "shined"—this allows him to see in the dark with no difficulty at all.
http://www.chess.com/groups/view/riddick-and-the-necromongers-man-vs-empire