Krawl Vortexes also known as Black Vortexes appear on the first two Spectrobes games, while they make no appearence in Origins.
Spectrobes
In the original Spectrobes, the vortexes appear as black swirling whirlpools. These have any property of Krawl.
Spectrobes: Beyond the Portals
In Spectrobes: Beyond the Portals, these Krawl Vortexes have color. Green vortexes signify Krawl of the Aurora property, blue vortexes contain Krawl of the property Flash, while red vortexes have Corona property Krawl. There are large vortexes, usually surrouned by a small vortex, a little bigger than Rallen. The large vortexes contain 1-3 battles in a row, while the smaller ones contain 1-2 battles. When fighting a boss, the boss turns into a large black swirling whirlpool.