Sources
CR
Type
Size
Alignment
Movement

Duergar Screamer

Medium Construct (dwarf), Any alignment

Armor Class 15 (natural armor)
Hit Points 38 (7d8 + 7)
Speed 20 ft.
STR
18
+4
DEX
7
-2
CON
12
+1
INT
5
-3
WIS
5
-3
CHA
5
-3
Damage Immunities poison
Condition Immunities Charmed, Exhaustion, Frightened, Paralyzed, Petrified, Poisoned
Senses darkvision 60 ft., passive Perception 7
Languages understands Dwarvish but can't speak
Challenge 3 (700 XP)

Actions

Multiattack. The screamer makes one Drill attack, and it uses Sonic Scream.

Drill. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:10 (1d12 + 4) piercing damage.

Sonic Scream. The screamer emits destructive energy in a 15-foot cube. Each creature in that area must succeed on a DC 11 Strength saving throw or take 7 (2d6) thunder damage and be knocked prone.

Reactions

Engine of Pain. Immediately after a creature within 5 feet of the screamer hits it with an attack roll, the screamer makes a Drill attack against that creature.

Lore

Creative duergar engineers have built numerous war machines, including some that can be fused with a duergar. Such a duergar-machine hybrid is fueled by the duergar's psionic energy, and the duergar inside the machine can psychically channel pain into power when attacked.