Hollow Knight: Silksong offers a non-linear journey, encouraging extensive exploration across its challenging landscapes. During your travels, you`ll encounter various unique Non-Player Characters (NPCs) who offer special quests called Wishes. One such encounter is with the Seamstress in the Far Fields, who will present you with the Flexile Spine Wish. This quest requires you to gather 25 Spine Cores. Fortunately, these crucial items are not difficult to locate.
Where to Find Spine Cores in Hollow Knight: Silksong
To acquire Spine Cores, you need to seek out creatures called Hokers. These enemies appear as floating white orbs adorned with a green beard and spikes. From the Seamstress`s dwelling, proceed to the right; you`ll soon find several chambers teeming with Hokers, making your search for the required items quite convenient.

Crucially, your objective isn`t to defeat these enemies outright, but rather to collect their projectile spikes. Each strike you land on a Hoker will cause it to launch spikes that embed themselves into environmental surfaces. You must then hit these embedded spikes to release an orb, which contains a Spine Core. Repeat this process 25 times to fulfill the quest requirement.
A single Hoker can withstand three hits before being vanquished. To maximize your Spine Core yield from each Hoker, the optimal strategy is to strike them once, then allow them to regenerate their spikes before hitting them again. Striking a Hoker before its spikes have fully regenerated will result in fewer Spine Cores collected from that specific enemy.

Furthermore, be aware that the spikes launched by Hokers will vanish after a short duration. Act swiftly to strike these spikes and collect their Spine Cores before they disappear.
Upon gathering all 25 Spine Cores, return to the Seamstress to claim your reward: the Drifter`s Coat. This valuable upgrade grants you the ability to glide after performing a jump and to utilize the air currents frequently found in the environment. With this new capability, your exploration potential will significantly expand.

