Swarm, Prismatic Beetles

Family: Insects Rodents & Vermin

Medium swarm of Tiny beasts, unaligned

Armor Class 13
Hit Points 38 (7d8 + 7)
Speed 20 ft., burrow 5 ft., fly 30 ft.

3 (-4) 16 (+3) 12 (+1) 1 (-5) 13 (+1) 2 (-4)

Skills Perception +3, Stealth +5
Damage Resistances bludgeoning, piercing, slashing
Condition Immunities charmed, frightened, paralyzed, petrified, prone, restrained, stunned
Senses blindsight 10 ft., darkvision 30 ft., passive Perception 13
Challenge 3 (700 XP)

Special 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 insect. The swarm can’t regain hit points or gain temporary hit points.
  • Glittering Carapace. The glossy, iridescent carapaces of the beetles in the swarm scatter and tint light in a dazzling exhibition of colors. In bright light, a creature within 30 feet that looks at the prismatic beetle swarm must make a successful DC 13 Wisdom saving throw or be blinded until the end of its next turn. If the saving throw fails by 5 or more, the target is also knocked unconscious. Unless it’s surprised, a creature can avoid the saving throw by choosing to avert its eyes at the start of its turn. A creature that averts its eyes can’t see the swarm until the start of its next turn, when it can choose to avert its eyes again. If the creature looks at the swarm in the meantime, it must immediately make the saving throw. The saving throw is made with advantage if the swarm of prismatic beetles is in dim light, and this ability has no effect if the swarm is in darkness.


  • Bites. Melee Weapon Attack: +5 to hit, reach 0 ft., one creature in the swarm’s space. Hit: 10 (4d4) piercing damage, or 5 (2d4) piercing damage if the swarm has half of its hit points or fewer. The target also takes 10 (4d4) poison damage and becomes euphoric for 1d4 rounds, or takes half as much poison damage and is not euphoric if it makes a successful DC 11 Constitution saving throw. A euphoric creature has disadvantage on saving throws.


A dazzling explosion of multicolored lights erupts from this cloud of flying beetles, flashing every color of the rainbow.


Flesh-Eating Beauties. The depths of the jungle are filled with lethal wildlife, and prismatic beetles are superlative examples of this. These flesh-eating, venomous insects distract and subdue their prey with sparkling beauty even as they devour it alive. Individual prismatic beetles sparkle like precious gems in the light; tosculi traders, gnolls, and humans often incorporate their carapaces into decorative jewelry or utilize them as special components in enchantment and illusion (pattern) spells and items.

Hypno-Paralytic. When swarming in the thousands, these beautiful bugs create a hypnotic cascade of glimmering hues capable of enthralling creatures. As they descend on their dazed prey, the beetles’ bites slowly paralyze their victims while their toxins distract the mind with feelings of euphoria and delight.

Predator Partners. Although carnivorous, prismatic beetles are not overly aggressive; they attack other creatures only when hungry or threatened. Even when they’re not attacking, however, they can be a threat; more than one unwary traveler has stopped to admire what they thought was a docile swarm of prismatic beetles, and became captivated. The unfortunates are often killed and eaten by lurking jungle predator, as such animals know the beetles stun and confuse prey.

An individual sluagh has a challenge rating of 1/8 (25 XP), 2 hit points, and does 3 (1d6) cold damage. They travel in swarms for a reason.

Section 15: Copyright Notice

Tome of Beasts. Copyright 2016, Open Design; Authors Chris Harris, Dan Dillon, Rodrigo Garcia Carmona, and Wolfgang Baur.