Final Fantasy Tactics Advance/Desert Peril

Desert Peril will be your second monster encounter. Before this battle, all of your missions except for Herb Picking have had you fighting units with classes that your characters can change into. The next few enemies you will fight will put you in a predicament.

Pre-Battle
After finishing The Cheetahs, make sure your team is ready. You can continue fighting other clans and doing quests. There are some quests though that have a unit called a Goblin, which is a blue humanoid monster with a big head. These things will die out eventually, so you'll want to catch one using a hunter's abilities and make a human that knows the Blue Magic ability Learning learn the ability.

Strategy
Now this is a different set of guys than you are accustomed to fighting. These monsters have no weapons or armor, so if you have Steal:Weapon or Steal:Armor, they won't help in this battle by decreasing stats. The Coeurl is at the top of the rock formation at the top of the screen, so if you send a unit there to fight it 1-on-1, it'll stay there.

All 3 units of the panther genus (coeurl and the red panthers) all have a passive ability called Reveal. In the game the passive ability is called the Support ability, therefore most of the time it is denoted as Reveal (S). Reveal allows the panthers to see hidden units. That means that sniper who used conceal is still a target for the panthers. So don't go into battle with a sniper assuming Conceal is going to help you at all. The panther's don't have much going for them past that, but they will later in the game.

The Antlion is an interesting unit, for it is of the bug genus. At the moment is only have LV3 Def-less and Sandstorm. Both can be very bad for you, but there are ways around it. Make sure no character has a level multiple of 3 (3,6,9,12,15...), and always stay a couple of steps ahead of this guy. Use ranged weapons to take him out without a problem.

The biggest threat will be the Cream of the flan genus. All flan are element based (Ice, Fire, Thunder). You are facing a Thunder Flan, also known as a cream. It will absorb and heal if hit by thunder-based attacks. That being said, it will heal itself by casting Thunder or Thundara on itself, while damaging people nearby. This guy is a pain, so if you can get a Black Mage, Red Mage, or some sort of unit to stop or slow it, the fight against this guy will be a lot easier.