When you Ctrl+C maps it shows the organs that bosses can drop. However this is incorrect now and not needed.
From the 3.9.1 patch notes: Every Map Boss can now be chosen for all organ types for Metamorph League. This will result in an even distribution of the different organs to use in Tane's Laboratory.
And while I'm here, Acid Caverns doesn't list the boss - it's 2 random members of the Chaos Renegades Warband.
When you Ctrl+C maps it shows the organs that bosses can drop. However this is incorrect now and not needed.
From the 3.9.1 patch notes: Every Map Boss can now be chosen for all organ types for Metamorph League. This will result in an even distribution of the different organs to use in Tane's Laboratory.
And while I'm here, Acid Caverns doesn't list the boss - it's 2 random members of the Chaos Renegades Warband.