This article lists all codex entries in the Creatures section in Dragon Age: Inquisition. When in game be sure to note the two diamonds which appear in the upper right corner of each creature codex. One diamond filled indicates you have killed this creature at least once before (generally the requirement to obtain the codex), two filled diamonds indicate you have fully researched this creature at the research table (at your base) and a message on the bottom of that codex should now tell you the benefits you have gained from it. The small icons on the left also have a research progression bar which can help you tell how far you are to completing research on that creature.