I don't believe old dimshimmer doesn't spawn any more or that the item doesn't drop. I have had people they told me they saw him up recently. Multiple people. I've heard from guildmate druids that have seen this item and were aware of it. The last one was on the EC market in Feb 2025.
I have camped him for about 16 hours. Not one spawn. For the first 14 hours I farm all the hatching lings near the place holders. I also tried just sitting at 0,0 just clearing that section.
near hour 14 I started to believe the hatchlings aren't the place holders or there are more mobs in the spawn group.
I decided to take a look at
https://www.takproject.net/allaclone/ datebase it shows more possible PH.
a_fae_drake (40%)
a_fae_drake_hatchling (20%)
a_mist_wolf (15%)
a_wasp_soldier (10%)
a_giant_spider (10%)
Old_Dimshimmer (5%)
I know the tak project is technically out of sync with p99... but its the closest open reliable date source.... considering its locked in Planes of Power era.
I got a little extra nerdy and spun up my own tak database and the data above matched.
I will find this item or my family won't have a Christmas.