Swarm of Cranium Rats

CreatureMPMMp. 832014

Medium aberration, lawful evil

Armor Class
12
Hit Points
76 (17d8)
Speed
30 ft.
Challenge
5 (1,800 XP)
STR
9
-1
DEX
14
+2
CON
10
+0
INT
15
+2
WIS
11
+0
CHA
14
+2
Damage Resistances
bludgeoning; piercing; slashing
Condition Immunities
charmed; frightened; grappled; paralyzed; petrified; prone; restrained; stunned
Senses
darkvision 30 ft., passive Perception 10
Languages
telepathy 30 ft.

Traits

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.

Telepathic Shroud.

The swarm is immune to any effect that would sense its emotions or read its thoughts, as well as to all divination spells.

Actions

Bites.

Melee Weapon Attack: +5 to hit, reach 0 ft., one target in the swarm's space. Hit: 14 (4d6) piercing damage, or 7 (2d6) piercing damage if the swarm has half of its hit points or fewer, plus 22 (5d8) psychic damage.

Bonus Actions

Illumination.

The swarm sheds dim light from its brains in a 5-foot radius, increases the illumination to bright light in a 5- to 20-foot radius (and dim light for an additional number of feet equal to the chosen radius), or extinguishes the light.

Spellcasting

Spellcasting (Psionics).

As long as it has more than half of its hit points remaining, the swarm casts one of the following spells, requiring no spell components and using Intelligence as the spellcasting ability (spell save DC 13):

Raw data
{
  "ac": [
    12
  ],
  "cr": "5",
  "hp": {
    "average": 76,
    "formula": "17d8"
  },
  "cha": 14,
  "con": 10,
  "dex": 14,
  "int": 15,
  "str": 9,
  "wis": 11,
  "name": "Swarm of Cranium Rats",
  "page": 83,
  "size": [
    "M"
  ],
  "type": {
    "type": "aberration",
    "swarmSize": "T"
  },
  "bonus": [
    {
      "name": "Illumination",
      "entries": [
        "The swarm sheds dim light from its brains in a 5-foot radius, increases the illumination to bright light in a 5- to 20-foot radius (and dim light for an additional number of feet equal to the chosen radius), or extinguishes the light."
      ]
    }
  ],
  "speed": {
    "walk": 30
  },
  "trait": [
    {
      "name": "Swarm",
      "entries": [
        "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."
      ]
    },
    {
      "name": "Telepathic Shroud",
      "entries": [
        "The swarm is immune to any effect that would sense its emotions or read its thoughts, as well as to all divination spells."
      ]
    }
  ],
  "__prop": "monster",
  "action": [
    {
      "name": "Bites",
      "entries": [
        "{@atk mw} {@hit 5} to hit, reach 0 ft., one target in the swarm's space. {@h}14 ({@damage 4d6}) piercing damage, or 7 ({@damage 2d6}) piercing damage if the swarm has half of its hit points or fewer, plus 22 ({@damage 5d8}) psychic damage."
      ]
    }
  ],
  "resist": [
    "bludgeoning",
    "piercing",
    "slashing"
  ],
  "senses": [
    "darkvision 30 ft."
  ],
  "source": "MPMM",
  "passive": 10,
  "hasFluff": true,
  "hasToken": true,
  "miscTags": [
    "AOE",
    "MW"
  ],
  "alignment": [
    "L",
    "E"
  ],
  "languages": [
    "telepathy 30 ft."
  ],
  "senseTags": [
    "D"
  ],
  "soundClip": {
    "path": "bestiary/swarm-of-cranium-rats.opus",
    "type": "internal"
  },
  "damageTags": [
    "P",
    "Y"
  ],
  "environment": [
    "underdark",
    "urban"
  ],
  "languageTags": [
    "TP"
  ],
  "otherSources": [
    {
      "page": 133,
      "source": "VGM"
    }
  ],
  "spellcasting": [
    {
      "name": "Spellcasting (Psionics)",
      "type": "spellcasting",
      "will": [
        "{@spell command}",
        "{@spell comprehend languages}",
        "{@spell detect thoughts}"
      ],
      "daily": {
        "1e": [
          "{@spell confusion}",
          "{@spell dominate monster}"
        ]
      },
      "ability": "int",
      "displayAs": "action",
      "headerEntries": [
        "As long as it has more than half of its hit points remaining, the swarm casts one of the following spells, requiring no spell components and using Intelligence as the spellcasting ability (spell save {@dc 13}):"
      ]
    }
  ],
  "hasFluffImages": true,
  "alignmentPrefix": "Typically ",
  "conditionImmune": [
    "charmed",
    "frightened",
    "grappled",
    "paralyzed",
    "petrified",
    "prone",
    "restrained",
    "stunned"
  ],
  "spellcastingTags": [
    "P"
  ],
  "conditionInflictSpell": [
    "charmed",
    "prone"
  ],
  "savingThrowForcedSpell": [
    "wisdom"
  ]
}