Iron Cobra Conversion Feedback Request

[InkwellIdeas]

Looking to get 2nd and 3rd opinions on this guy:

Iron Cobra
Small Construct, Unaligned

Armor Class 24 (natural armor)
Hit Points 22 (4d10)
Speed 40 ft.

Str 16 (+3) Dex 16 (+3) Con 18 (+4)
Int 3 (-4) Wis 10 (+0) Cha 1 (-5)

Damage Immunities fire, poison, psychic; piercing and slashing from nonmagical weapons that aren't adamantine
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses darkvision 60ft., passive Perception 10
Languages understand the languages of its creator but can't speak
Challenge 4 (1,100 XP)

Find Target. Once per day, the iron cobra's creator can order it to find and kill a specific creature within one mile, which it does as if guided by the spell Locate Object (with a changed duration.) The creator must have seen or be holding an object from the specified creature for this to function.

Actions
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 14 (1d8 + 3) piercing damage and the target must make a DC 12 Constitution saving throw, taking 13 (3d8) poison damage on a failed save. Poison may only be used 3 times until refilled.

Thank you!

 

[Redthistle]

This is a nasty piece of work; thank goodness for the low hit points.

First, which edition did you use to convert this from?

Per the DMG, AC = 10 + Dex mod + natural armor, in this case giving a natural armor of +11. That's off-the-charts in 5e; an iron golem has only AC 20 including its natural armor; a gorgon, AC 19. Even the most powerful ancient dragons top out at AC 22. I'm thinking that you'll want to take that AC down, probably comparable to the iron golem.

Damage Immunities. These mostly make sense. However, your description of immunity to slashing and piercing damage (but not bludgeoning) unless a nonmagical weapon is adamantine. What's your reasoning on the exception allowing bludgeoning damage? Unless there's a specific reason for this, perhaps you should simply copy the iron golem's damage immunities.

Condition Immunities. These match the iron golem, so they're good.

Senses: Here, I'd be inclined to give the iron cobra advantage on Wisdom (Perception) checks based on touch, a kind of "tremor-sense".

Find Target. I like this, although the spell should be Locate Creature, not Locate Object, and I'd like some clarification on what you mean specifically by "with a changed duration."

Actions. Looks good. I appreciate that the poison can only be utilized three times before being recharged.

 

[InkwellIdeas]

Thanks for the feedback.

The AC was a typo, It should be an 18. (I was patterning it off of the Iron Golem, but figured this guy is smaller so it should be less.)

I dropped bludge becuase I felt that bashing it should be more likely to have an effect than pierce/slash. Like metal will bend/give a little when you smack it with a hammer, but slash it with a knife doesn't do much. Again though, maybe I should add bludge back in as the 5e designers used it for the Iron Golem.

Thanks for the tremor-sense idea.

Yeah, Locate Creature seems a better fit. "with a changed duration" should have been "range" as I'm extending the range to 1 mile. 1000ft doesn't seem as useful for a wizard to make this construct, then release it and have it only work within 1000'. Part of me wants to make it 10 miles so if the target is within a half-day, it can find the victim-to-be.

 

[InkwellIdeas]

I also caught a typo on the bite damage.