Sources
CR
Type
Size
Alignment
Movement

Iron Cobra

Medium Construct, Unaligned

Armor Class 13
Hit Points 45 (7d8 + 14)
Speed 30 ft.
STR
12
+1
DEX
16
+3
CON
14
+2
INT
3
-4
WIS
10
+0
CHA
1
-5
Skills Stealth +7
Damage Immunities poison; bludgeoning, piercing, slashing, from nonmagical attacks that aren't adamantine
Condition Immunities Charmed, Exhaustion, Frightened, Paralyzed, Petrified, Poisoned
Senses darkvision 60 ft., passive Perception 10
Languages understands one language of its creator but can't speak
Challenge 4 (1,100 XP)

Traits

Magic Resistance. The iron cobra has advantage on saving throws against spells and other magical effects.

Actions

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit:6 (1d6 + 3) piercing damage. If the target is a creature, it must succeed on a DC 13 Constitution saving throw or suffer one random poison effect:

1. Poison Damage: The target takes 13 (3d8) poison damage.

2. Confusion: On its next turn, the target must use its action to make one weapon attack against a random creature it can see within 30 feet of it, using whatever weapon it has in hand and moving beforehand if necessary to get in range. If it's holding no weapon, it makes an unarmed strike. If no creature is visible within 30 feet, it takes the Dash action, moving toward the nearest creature.

3. Paralysis: The target is paralyzed until the end of its next turn.

Lore

The gnomes' efforts to invent and tinker with magic and mechanical devices produce many failed constructs, but also result in genuine advances, such as clockworks. Since their discovery, the methods used to craft clockworks have passed from one community of gnomes to another and down the generations.