Due to the nature of how the deviation of Goo Girls being rather slimy, they drop a goo-like substance similar to a slime core, but it much more mailable into armory than typical slime cores, and offers more advanced defense. This is considered to be very useful, but it also difficult to obtain Goo because these "goo girls" can be very dangerous to the unprepared adventurer, even after the changes introduced within the Augmented Reality patch.

Many properties of Goo remain unknown to the playerbase currently, but as time goes on this will definitely change.