Mylaks are essentially small orange bubbles dwelling on the surface of planet Onnec’s acid seas. They reproduce by fission and die when they are popped. Although they possess little intelligence of their own they can be easily used by one with a strong mind to generate sophisticated illusions.
Dyn, lord of the acid seas, uses them for just that to test visitors. When the test is failed the Mylaks will instinctively cluster together and harden, trapping the visitor beneath the surface. When someone refuses to go in at all, they can be ordered to use a collective power, to immobilize the person, and then suck them under. Their intelligence is sufficient enough that they will manically laugh and taunt these people.