Barren Wasteland is the fifth stage in the game. It does not contain a boss.
A guy who wants you to help him kill a Gryphon is present in this dungeon.
Statues that shoot lion head-like projectiles and cacti can be found here. They damage both ally and foe alike.
Red Lizard - A lizard with blue stripes that shoots fireballs.
Blue Snake - A three-headed snake with fire elemental abilities. A red version of this monster exists.
Serpent Woman - A monster with the ability to fire homing projectiles.
Harpy - Shoots wind blades that go backwards.
Scorpion - Has an attack that causes Shock and Poison. Can dash.
Weapons that give +20 to stats can be found here.