From the publisher:
Combat, Only Faster!
Keeping track of initiative in games using the d20 System can get complicated. Every GM has a method that he or she favors, but which sometimes lacks in versatility or utility. Initiative Cards provides GMs both with an easy way to keep track of initiative, and a handy reference for all the sorts of information a GM sometimes needs during a game session. Initiative Cards do not replace monster sourcebooks, but they contain all the information needed to track and speed combat.
Initiative Cards: Monster Set 1 is a PDF for GMs containing pre-filled Initiative Cards for 348 monsters, as well as instructions for use and blank cards for characters and monsters.