Being a fiend that, unable to move and hunt for food on its own, mimics the form of a crystal, thereby tempting its prey to come to it. The deception is nearly perfect and thus almost impossible to detect. Should an ill-starred traveler mistake such a creature for a crystal, and reach out his hand, he will be treated to a maelstrom of the strongest magicks, before having his life juices summarily drained.
The Crystalbugs know elemental magicks, halve all elemental damage, are immune to many debuffs and have the troublesome Restore ability. Like Mimics, they will not attack until inspected. Crystalbugs do not give any Experience Points, but they do give 10 License Points.
The Crystalbug must be attacked consecutively, as otherwise it will resort by using Restore to heal itself for 30% of its HP.
The red Crystalbug is difficult if the party's level is not over 40. The party should have Shell and Haste before interacting with the false Gate Crystal, as the Crystalbug will cast Darkra or a similar spell immediately after. Bravery and Berserk are also recommended, but at least one of the party members should be the dedicated healer.
The party should keep attacking the red Crystalbug with normal attacks. Using elemental magick is pointless as only non-elemental attacks deal full damage.