D&D 5E Nearly unhittable monster with 1 hit point

[Acheron42]

I'm toying with making a new monster. One of the games i Dm has level 5 players who have been doing well against about level 8 challenge rating. Anything lower and they just decimate it in one round. I came up with a new idea for a monster to challenge them but i need some help fine tuning it. Here are the stats i had in mind.

Yuan ti maniac
Size medium
Hit points 1
Ac 15
speed 60
Str 14 Dex 20 Con 14 Wis 3 Int 3 Cha 3

Attack
Claws +4 to hit damage 1d4 +2

Features
When targeted by and attack it makes a Dexterity saving throw dc 12 on a success before the attack hits move up to it's full movement out of range of the attack.

Dash as a bonus action

I may also make an elite one with slightly higher hit points and ac.

 

[GMforPowergamers]

I have played with 'armored kobolds' that are AC 21 (full plate, shield, skill and ring of prot) and only have 18hp... I gave them a good +6 to hit and a +1 short sword (so 1d6+2 damage) and threw 4 of them mixed in with some hobgoblins at level 7 and they were a menace...

the only 5e fight we had worse was the summoned and buffed elementals... 2 invisible stalkers resstance to non magic weapons and invisable where bad enough with 14 ACs buffing them to 17 ACs made that fight last for ever

 

[Bradley Hindman]

Features
When targeted by and attack it makes a Dexterity saving throw dc 12 on a success before the attack hits move up to it's full movement out of range of the attack.

Targeting is a bit of a strange trigger. Presumably, once the maniac has made its escape the attacker is free to attack someone else or move and then take an attack. What happens if the attack is a ranged attack? Could an archer plink the maniac after it has skittered off? If yes, note that the quoted feature doesn't require that the maniac use its reaction, so an archer could repeatedly target the same maniac until the maniac has moved out of range, potentially a very long way.

 

[MarkB]

Sounds like something that might give PCs a hard time once, after which they use movement-inhibiting (or saving-throw-inhibiting) abilities to keep the critter pinned down.

 

[Zaran]

A Wizard with Magic Missile would rule that fight. Those maniacs would really only be a menace to martial characters. If that's what you want, then why not take that DC save out and just add to their AC? They have a 14 out of 20 chance to avoid taking damage so just make their AC like 22 where it takes a die roll of like 15 to hit them? Defense rolls aren't core because that takes extra time to do.

 

[Bradley Hindman]

A Wizard with Magic Missile would rule that fight.

This was my first thought as well. But, the spell magic missile targets the opponent and it seems like an attack to me. So, shouldn't it also trigger the critter's "escape feature".

 

[iserith]

Give it one hit point, expertise in Stealth, and the following trait and reaction:

Trait

Camouflaging Scales. In a natural environment, attacks against the yuan-ti have disadvantage.

Reaction

Defensive Spray. When the yuan-ti is missed with an attack, it can spray a stream of blinding poison at a target with 10 feet. The target must make a DC 13 Dexterity saving throw or be blinded for 1 minute. An affected creature can repeat this saving throw at the end of each of its turns to remove the effect.

The smart play is to fight it indoors, seek advantage if fighting it outdoors (reckless, help, etc.), attack it from range (so give it a bow to counter that), or throw save spells (or magic missile) at it.

 

[Acheron42]

I'm glad i posted. I don't think that will work the way i wanted. I may have to go with some sort of ressurection anf multiplication feature instead to get the desired effect.

 

[MarkB]

How about using the zombie's Undead Fortitude feature, with a greatly reduced DC?

 

[ExploderWizard]

I'm toying with making a new monster. One of the games i Dm has level 5 players who have been doing well against about level 8 challenge rating. Anything lower and they just decimate it in one round.

Seems like a nice challenge to me. At that rate its a 10 round fight. Doesn't sound like a cakewalk at all.