Both the screamer and the hammerer are duergar trapped within machines, however the duergar screamer is stripped of its beard:
Duergar accused of spreading gossip or plotting against their superiors are trapped within one of these devices, their beards shorn and their ongoing agony channeled into psionic energy that powers the screamer.
Also, the Duergar Hammerer has a claw and a hammer attack, while the Screamer has only a drill attack.
Since the image cleary has a claw and a hammer, and the duergar is bearded, that is a duergar hammerer.
mlenser
commented
2 years ago
https://www.kryxrpg.com/creatures/duergar-screamer
Both the screamer and the hammerer are duergar trapped within machines, however the duergar screamer is stripped of its beard:
Also, the Duergar Hammerer has a claw and a hammer attack, while the Screamer has only a drill attack.
Since the image cleary has a claw and a hammer, and the duergar is bearded, that is a duergar hammerer.