All encounters you come across in the game can be divided in twelve groups: humans, demi-humans, plants, beasts, bugs, fish, birds, undeads, demons, dragons, mechanicals and magicals. Recognizing an enemy's type can be useful since enemies with the same type tend to share certain characteristics. Additionally, there are also skills in the game which are only veryagainst one specific type.
The human-type is pretty straightforward: it consists of humans. While humans don't appear very often as random encounters, the human-type is fairly common among forced battles and boss battles. Most of the game's heroes also have the human-type. Humans are usually not weak to any element in particular, although non-corrupted humanoids are often weak to dark-elemental damage.
The term demi-humans was coined to describe all creatures that are humanoid in appearance, but aren't really human. For example, the common goblin and imp enemies are in this category. One should also think of intelligent life-forms closely related to humans, such as elves, dwarves, fairies and kobolds. These are also demi-humans. So you see, it's quite a big and diverse group. Ice often works well against demi-humans.
The plant-type consists of trees, shrubs, flowers, herbs, mushrooms, and so on. While of course the entire world is scattered with these, most of them will not harm you - or even acknowledge your existance, for that matter. For the ones that do, you should use fire magic to take quick care of them. When dealing with plants, you should stay clear of water or earth magic since most plants are immune to those elements (or absorb them, even). Usually, plant-type monsters aren't very tough, although they can be a nuisance because they generally like to inflict status ailments such as poison on you.
The beast group is a very large group. Basically, it consists of all animals that are not already covered by the other groups (bugs, fish, birds or dragons). The two most common groups of beasts in the game are mammals (like horses, wolves and bats) and reptiles (like crocodiles, lizards and snakes). One thing almost all beast-type monsters have in common is their weakness to ice magic.
Bug-type enemies, such as bees, spiders and ants, are usually quite easy to deal with. They are usually very small and may often appear in large groups. Although bugs are mostly very fast, the rest of their stats are almost always below par. Insects are usually weak to several elements, especially fire, thunder and wind.
Oceans, seas, rivers and lakes are the domain of fish-type encounters. You can expect to run into them frequently when you're travelling by ship. Fish come in many different sizes; from are cute little goldfish to colossal whales. Obviously, fish-type creatures are closely related to the water-element and as such are almost always vulnerable to the thunder (or grass) element.
The bird type is rather rare. While birds are of course very common, there are only a few aggressive birds that will actually attack you. Birds you'll encounter in battle are usually flying (chickens are a notable exception) and thus vulnerable to wind-elemental magic. It should be noted that bats are *not* birds, but mammals (and thus beasts)!
Undeads are a fairly easily distinguished group. They all look pretty.... dead. The most common undeads are zombies, but of course ghosts, vampires, wraiths, and such are also undead. Undeads are always weak to holy-elemental damage, and often
Demons are somewhat difficult to distinguish. They can have many forms, not just the typical devil look. If something looks really fiendish, but it's not undead, there's a good chance it's a demon. Possessed items, that normally wouldn't be able to attack you, such as books or jars, are also counted as demons. Although demons do not have one specific weakness, holy-elemental damage usually works well against them since many demons have an affinity with the dark element.
Dragons mostly have the shape of a very large lizard. They usually have wings, but they may also appear without them. In any case, they are much stronger than regular reptiles. Dragons are truly among the most majestic and powerful of creatures, and tend to rather difficult to defeat. Flamizards are also counted as dragons, although they are inferior to the more 'pure' dragons. Generic dragons do
Mechanical monsters are quite rare, as they do not "naturally" inhabit this world. They have to be constructed first. Historians say that the ancient people of Tunaqua knew how to do this. Mechanical monsters are practically always made out of a metal alloy, so you should recognise them easily. Note that weapons themselves, such as cannons, also belong to this category. Mechanical creatures are almost always extremely weak to thunder, and often to water as well.
And finally, we have the smallest group; the magical beings, also known as "elementals". These are pure manifestations of magic. Much like demons, they may vary in form. An example of a pure magical being would be a conjured ball of fire or cyclone. So-called "formless" opponents, excluding ghosts, are also magicals. Pure magical creatures that are aligned to one specific element are usually weak to the opposite of their element. For instance, a wind elemental is weak to earth, while a fire elemental is weak to both ice and water.