They Grow Up So Quickly

Looks like the turn-in point with Reldorn is 25.4, 17.7. (My target had focused on the weekly thing instead of on him and it was rough to find. If you lose your gorm, though, you can go back up to the trough and pick it up again, and it will still be at the growth stage it was at when you lost it.)

BUG FOUND 9.1.5
When you gain the ability "Spectral assassin" from Fangcrack - this makes you invisible out of combat.

Due to this, when you order your gorm to eat the corpse after combat, the invisible buff causes the Gormling stop eating.

Workaround: Stay in combat while your Gorm eats.

Choose a gormling by interacting with it, then kill mobs in the surrounding area and use quest item ([item=186089]) on their corpses to order your gormling to eat them. Note that while the gormling will eat any nearby corpses, you still need to target one of the corpses in order to use the staff.

Tips: Edible corpses will glow with an outline, if you have outlines enabled in your graphics settings. Watch for the staff symbol on the nameplates to see which mobs will contribute to this quest. (I think it's most of them.)

I encountered an issue where nothing happened when I clicked the staff (it didn't even go on cooldown). A quick /reload fixed it. I've also had issues with disappearing corpses. The whole quest seems kind of glitchy.

Once the quest bar is full, click on the gormling to mount it, and turn in the quest at /way 25.4 17.7