For those on TLPs looking to do some epic 1.5 work pre-OoW era, these do not appear to spawn until OoW. This page lists them as a Ykesha era mob, but I could find no spawns (PHs or otherwise) for these mobs in GoD era at the listed locations, so I would assume they don't even spawn until OoW unlocks.
Edit: Follow-up, the PHs and Delirious Drogmor began spawning when OoW unlocked. So there ya go.
9 May 2023
Yelinak TLP
Gates of Discord era
Edited 6/27/23
Yelinak TLP
Omens of War Era
Edited, Jun 28th 2023 1:39am by Erekai