RAVEN
Raven is located in the Western Forest and has a decent robe and staff.


The Stranger


The Stranger is located on the continent of Sakai. He has fangs which are good for regeneration as well as a decent cloak and ring.


Chilblain is located in the Glacial Flats along with other frost drakes. He sometimes has a nice dagger weapon when killed.
Chilblain
There are many monsters throughout the realm. Some are powerful and unique, others are mundane and easily slain. Some powerful monsters are extremely difficult to solo. Here are a few named ones of note (list is not all inclusive):
Astarian Continent: Troll King, Raven, Athius, Volker, Daithen, Zgral, Casey, Beldegar, Dream Master, King Ramsunder, Magical Unicorn, Vengar, Chilblain, Drow Priestess, Magnemmar
Altheon Continent: Surgeon, Sargual, Udo, Theodus, Eclerdia, Lysel
Sakai Continent: Sato Ichi, Shinzu, Ryu, Stranger, Genie Master (Note: New Sakai is similar in layout to the Old Sakai and the mobs have similar names. I am not sure if they will merge or sink old Sakai at some point)
The directions to these monsters can usually be found in your guild tome which is obtained from your Guild Trainer. There is frequently valuable treasure after slaying these monsters.
Mundane monsters (e.g. mobs) can be found in any of the tens of thousands of rooms in the realm. Some will hold you in the room, some will auto-attack you. It is a dangerous world.