Bestiary is now pretty much finished.
As I said, it reveals more information depending on the number of kills. You can switch between the drops and description windows and you can scroll windows down and up.
Drops work as you might expect. If enemy drops an item, it will appear in the bestiary together with its drop rate. Items you didn't get from that enemy yet will display as "???" so you know exacly how many items are missing.
Two more things for me to do. Actualy add all enemies currently in the game and make the amount of kills influence the combat in some way.