For Once It Isn't Guano

For Once It Isn't Guano is a Tome of Knowledge Bestiary entry for Bat, Giant.

Instructions: Order & Destruction

Kill a 'Neborhest Bat' in Marshes of Madness in Order PQ 'The Tower of Neborhest' area (43.5k 54k) or just before at 35k 51k.

Or

Kill 'Leatherwing Bat' or 'Blighted Leatherwing' in Troll Country in a large zone around 15k 48k/11k 38k, to trigger the unlock.
Kill them until they drop a Pocket Item 'Bat Wing'. Equip it for the associated title.