sentences:  Appearing in the series VI episode "Psirens" (1993), Psirens are GELFs which can telepathically alter the perception of humans, in order to suck out their brains with a straw.In their natural form, Psirens are insectoids standing at around two metres high and look something like giant Assassin Bugs, with giant bulbous eyes and a large carapace.Their name and manner are similar to the Sirens of Greek mythology.