Here's the world map.  Its a 327 KB JPG image. Refer to "Random Monster Areas" for which monsters are in which area.  
 
 

 
 
  As you enter different territories, you'll meet different groups of monsters. The world map has each territory marked. Use the color groupings below as a guide, but not all the monsters are listed in each level group.  
 

Levels 1-8

Spider
Laluhn
Slime
Heckett
Lich

 
 

Levels 9-18

Chimera
Gozuki
Griffen
Blue
Banshee

 
 

Levels 19-27

Cancer
Owl
Wings
Atlas
Guy

 
 

Levels 28-36

Medusa
Nue
Hangman
Fenrir
Radon

 
 

Levels 27-35

Baram
Salamand
M-Eater
Bones
Scylla

 
 

Over 45

Tsu
Jinn
Fury
Anubis
Scorpio