Legendary Elder Mountain Troll
The summon requirements for the legendary elder mountain troll appear to be incorrect. They are not in line with the material costs of any of the other summons.
To summon this legendary you require 40x Hardened Skin, which is only a 1.5% drop rate from Mountain Trolls, or a 5% drop rate from Elder Mountain Trolls (there are zero permanent spawns of Elder Mountain Trolls, only random chest spawns)
Other legendary summons which require a 5% drop rate item only require 5-10 of that item, not 40. As it stands right now this legendary is not summonable with any reasonable amount of effort.
It would make more sense if this required 40x Mountain Troll skins, not the rare drop.
We have reasons to believe that the summon itself is bugged and that it will summon just a common elder mountain troll.