Yoggie

 is an item that is dropped from Yog in the Crystal Hollows with a 6% chance,  from the Bal boss in the Khazad-dûm], and from treasure chests in the Magma Fields.

It can be used to upgrade Flamebreaker Armor to the Yog Armor, and 100 can be used to upgrade the Bal Pet from to  (in addition  to  and two days).