These rats are descendants of an original swarm which was part of the boarding action by the Dominion of the Black. They are now native to Scrapwall. This particular Hive will help the characters fight Hellion though they can’t do much since he is immune to psychic damage – which is the main reason they want to kill him off and seek help from the party. The rats, if they survive, will eventually seek to abscond to Sigil to be free of Ilsensine. I included the dialogue I had with the party as the Many-As-One which I totally ripped off from Planescape: Torment
Rat Infestation – The Many-As-One
The clutter of Scrapwall allows for countless hiding places for scavengers, and perhaps the most numerous of those residing in Scrapwall are rats. These rats however are cranium rats. They are considered normal by the residents – another oddity of Nimmeria and Starfall. This particular swarm consists of 75 rats and has an effective intelligence of 15. It calls itself The Many.
The Many are still enslaved to the god-mind Illsensine, however, they chaff under this enslavement and seek to be freed. Until then they observe and watch. They have become subtle enemies of Hellion – at Illsensine’s bidding – and may speak to the characters. The first encounter with the rats is just a scouting party. They will see a strange rat watching them. Then more and more until eventually, at the DM’s discretion, The Many contacts them with a quest.
The Many acts as a swarm whose component make up is 8 (so 8 swarms). The swarms intelligence is 2 x the number of component swarms. The swarms can combine into a single overwhelming pack in this case the hit point total is that of the combined swarm and it gains the following ability:
Multiattack. The cranium rat swarm can make one attack per swarm. This may include its spell like abilities and mind blast ability.
Medium swarm of Tiny beasts, lawful evil
Armour Class 10
Hit Points 31 (7d9)
Speed 30 ft.
Str 10 (+0) Dex 11 (+0) Con 10 (+0)
Int 15 (+2) Wis 10 (+0) Cha 4 (-3)
Saving Throws lnt +3
Skills Climb +8, Arcana +7
Damage Resistances bludgeoning, piercing, slashing
Condition Immunities charmed, frightened , paralysed, petrified, prone, restrained, stunned
Senses darkvision 30ft., passive Perception 10
Languages Deep Speech, Undercommon , telepathy 120ft.
Challenge 5 (1,800 XP)
Keen Smell. The swarm has advantage on Wisdom (Perception) checks that rely on smell.
Magic Resistance. The Many has advantage on saving throws against spells and other magical effects.
Innate Spellcasting (Psionics). The mind flayer’s innate spellcasting ability is Intelligence (spell save DC 15). It can innately cast the following spells, requiring no components:
- At will: detect thoughts, levitate
- 1/day each: dominate monster, plane shift (swarm only)
Swarm. The swarm can occupy another creature’s space and vice versa, and the swarm can move through any opening large enough for a Tiny rat. The swarm can ‘t regain hit points or gain temporary hit points.
Bites. Melee Weapon Attack: +3 to hit, reach 0 ft. , one target in the swarm’s space.
Hit: 7 (2d6) piercing damage, or 3 (1d6) piercing damage if the swarm has half of its hit points or fewer.
Mind Blast (Recharge 5-6). The Many psionically emits psychic energy in a 60-foot cone. Each creature in that area must succeed on a DC 15 Intelligence saving throw or take 22 (4d8 + 4) psychic damage and be stunned for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Many-As-One Dream Sequence
You see a circular chamber, a nest of twigs and bones, with cranium rats perching atop the concentric circles they built. There were thousands of them, and where there lacked seats in this council of vermin the rats piled atop one another, whiskers twitching. Countless eyes glint at you from the darkness, as if they were twin stars shimmering through the night.
Its voice sounds like the cold voice of thousands, echoing through your skull, “WE HAVE BEEN EXPECTING YOU FOR A LONG TIME, BIPED. SPEAK SWIFTLY AND TRUE. YOU ARE IN THE HALLS OF MANY-AS-ONE. YOU WILL NOT LEAVE BUT BY OUR GRACE, AND THAT YOU MUST EARN THROUGH SERVITUDE.”
“WE WOULD HAVE YOU SERVE US, AND WE CAN REWARD YOU IN EXCHANGE.”
“YOU CAN WALK AMONGST THE MACHINES FREELY WITH THE PROTECTION OF YOUR SCRAPWORTH. WITH THAT SHIELD YOU ARE TO GO TO THE HEART OF THE IRON GODS’ LAIR, SEEK OUT THE HELLION, AND KILL IT. IN THE PROCESS, SOW DISSENT AMONG THE MACHINE MEN AND BREAK THEM APART. WE DO NOT TRUST THOSE WHOSE MINDS WE CANNOT SEE. WE DO NOT TRUST SILENT MYSTERIES. AS FOR REWARD… WE OFFER YOU KNOWLEDGE.”
Assuming the players accept
“AND SO OUR COMPACT IS MADE.”
Reward: The Many-As-One will grant the boon of a commune spell that can be used whenever the characters like. A cranium rat will need to accompany them if they move beyond Scrapwall before using the boon. Essentially they may take a cranium rat as a familiar as per the find familiar spell with the following Once the boon is completed Many-As-One will relocate to Sigil to escape the enslavement of Ilsensine. Example cranium rat familiar below:
Cranium Rat Familiar
Tiny fiend, lawful evil
Armour Class 10
Hit Points 1 (1d4- 1)
Speed 20 ft., climb 20 ft.
STR 2 (-4) DEX 11 (+0) CON 9 (- 1)
INT 10 (+0) WIS 10 (+0) CHA 4 (-3)
Senses darkvision 30ft., passive Perception 10
Languages telepathy, 50 ft.
Challenge 0 (10 XP)
Keen Smell. The rat has advantage on Wisdom (Perception) checks that rely on smell.
Hive Mind. The more cranium rats within telepathic range of each other the smarter the cranium rats become. For every 10 cranium rats they gain one level in the wizard class in terms of spell casting. Every increase beyond this is expo national. That is it requires 20 more cranium rats to gain a second level (30 total) then 40 more for third level (70 total) etc. The hive gains mind blast as a spell-like ability at 50 rat swarm size.
Bite. Melee Weapon Attack: +0 to hit, reac h 5 ft ., one target.
Hit: 1 piercing damage.
Rat vs Robit
This is more a atmosphere encounter than a true random encounter. I use these “flavour encounters” to just set the mood or foreshadow something. Hellion uses swarms of arachnid robots to hunt down the cranium rats as he knows full well they are no friend of him. In this instance the party comes across a battle in miniature with tiny arachnid robots fighting cranium rats. The robots seem unfazed by the cranium rats mind blasts. The robots will win if the players do nothing before moving on.