D&D 5E Help with a monster build- feedback appreciated!

[quexul]

Here is an ooze I built to throw at my 4th level players. This will be an encounter while trekking through the snow so it will probably be the only encounter that day. Let me know what you think.

Arctic Ooze
Large Ooze, Unaligned
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Armor Class 12
Hit Points 85 (10d10 + 30)
Speed 20 ft., climb 20 ft.
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STR DEX CON INT WIS CHA
16(+3) 5(-3) 16(+3) 1(-5) 6(-2) 1(-5)
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Damage Vulnerabilities fire
Damage Immunities cold, lightning, slashing
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, prone
Senses Blindsight 60 ft. (blind beyond this radius), passive Perception 8
Languages —
Challenge 4 (1,100 XP) Proficiency Bonus +2
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Amorphous. The ooze can move through a space as narrow as 1 inch wide without squeezing.
Cold. A creature that touches the ooze or hits it with a melee attack takes 4 (1d8) cold damage
Spider Climb. The ooze can climb difficult surfaces, including upside down on ceilings, without needing to make an ability
Icy Camouflage. While the ooze remains motionless, it is indistinguishable from a normal snow pile.

Actions
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Freezing Pseudopod. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit 6 (1d6 + 3) bludgeoning damage , plus 8 (2d8) cold damage, and the target must succeed on a DC 13 Constitution saving throw or is frozen. The frozen target is paralyzed and can’t move or speak. It takes 4 (1d8) cold damage each round it is paralyzed. It can repeat the saving throw at the end of each of its turns, ending the effect on a success.

Reactions
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Split. When an ooze that is Medium or larger is subjected to lightning or slashing damage, it splits into two new oozes if it has at least 10 hit points. Each new ooze has hit points equal to half the original ooze's, rounded down. New oozes are one size smaller than the original ooze.

(edited some damage, & damage vulnerabilities)

 

[J-H]

The Paralysis effect is going to be unpleasant for the players (which is fine), but they should shake it off pretty quickly.

It's a typical ooze encounter, except it sounds like it's going to take place in a literal wide-open white plain. Every single PC can outrun the ooze (unless paralyzed), so what prevents them from simply disengaging and leaving it behind, or kiting it with ranged weapons and cantrips?

If they run away, it can follow their tracks and attack later (while they fight something else), but it also has no ranks in Survival, so if they do anything that would plausibly deny it a trail (Pass Without Trace, cross a river, get into a no-snow area, etc.), it's gone.

#Ambushpredator problems

 

[GMMichael]

It's a typical ooze encounter, except it sounds like it's going to take place in a literal wide-open white plain. Every single PC can outrun the ooze (unless paralyzed), so what prevents them from simply disengaging and leaving it behind, or kiting it with ranged weapons and cantrips?

That's a good question. Answer: the arctic ooze now has Snow-Step. As long as it's moving through fresh powder (snow), it can use dimension door to catch prey. Leading to a likely scary impression that there are multiple oozes in the vicinity!

Is my mind wandering? I want to know what an arctic ooze eats. If it's not part of the ecosystem, how did it get there? Does it rejoin its fellow blobs after they've been split? Does it aspire to someday become a snow elemental?