Biweekly Monster-Arcandidae (and Swarm)

Another in my efforts create semi-sentient creatures with a shaman variant: Arcandidae.
Arcandidae are locust-like bugs with near sentience. Individuals have some cold affinity, but in swarms they have magical, instinctive dances that allow the swarm to cast powerful frost magics. They shed their chilly exoskeletons from time to time and they can be harvested and used in various concoctions. They lay eggs in the soil and, though hard to gather, they are also rumored to have powerful properties.

Arcandidae (Arcane Locust)
Tiny beast, chaotic neutral
Armor Class: 13
Hit Points: 2 (1d4)
Speed: 10 ft., fly 40 ft.
Strength: 2 (-4)
Dexterity: 14 (+2)
Constitution: 10 (+0)
Intelligence: 6 (-2)
Wisdom: 8 (-1)
Charisma: 2 (-4)
Damage Immunities: cold
Senses: blindsight 10 ft., passive Perception 9
Languages: –
Challenge: 0 (10 XP)

Actions
Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 1 piercing damage and 2 (1d4) cold damage.

Swarm of Arcandidae (Arcane Locusts)
Medium swarm of Tiny beast, chaotic neutral
Armor Class: 13
Hit Points: 56 (16d8-16)
Speed: 10 ft., fly 40 ft.
Strength: 13 (+1)
Dexterity: 14 (+2)
Constitution: 10 (+0)
Intelligence: 6 (-2)
Wisdom: 14 (+2)
Charisma: 2 (-4)
Damage Immunities: cold
Damage Resistances: bludgeoning, piercing, slashing
Condition Immunities: charmed, frightened, grappled, paralyzed, petrified, prone, restrained, stunned
Senses: blindsight 10 ft., passive Perception 12
Languages: –
Challenge: 6 (2,300 XP)

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 Arcandidae. The swarm can’t regain hit points or gain temporary hit points.
Innate Spellcasting. The swarm’s innate spell spellcasting ability is Wisdom (spell save DC 13). The swarm can innately cast the following spells, requiring no components:

At will: Ray of Frost
1/day each: Fire Shield (chill only), Cone of Cold, Freezing Sphere (self only)

Spell damage is half if the swarm has half of its hit points or fewer.

Actions
Bites. Melee Weapon Attack: +4 to hit, reach 0 ft., one target in the swarm’s space. Hit: 14 (4d6) piercing damage and 28 (8d6) cold damage, or 7 (2d6) piercing damage and 14 (4d6) cold damage if the swarm has half of its hit points or fewer.

In future weeks, I’ll be imagining uses for the shells and eggs of these pests. For now, check out some of the many trinkets and concoctions in my item compendium: Who Would Just Leave This Stuff.