Can't seem to find Corpeso

[Humanoïde]

So I'm in the end game and trying to get all the weapons. I've read that Corpeso can be dropped from ennemies in the Dark Shore but after farming them for roughly 30 minutes (and I 1-shot them so I had the time to rack up the kills) I still haven't found it.

No guide mentions a low droprate so I'm wondering if I'm doing something wrong here. Anyone has any idea ?