This is the magic-immune boss in AQ40, and the effect lasts after the boss dies, making it immune to the loot-a-rang toy.
Small bug with Emperor Vek'nilash
Sort of intended, Loot-a-Rang is a magic item and it won’t work on magic-immune mob. In old Kara raid, there’s a place with lots of floating wyrms that are also immune and can’t be picked up with the loot-a-rang either.
Odd but intended