2023 Advent Calendar Day 2: Giant Snowflake (monster)

Last year, I was disappointed in the official D&D advent calendar, which didn't have any actual game content. So I decided to make my own.

This, but at 300 rpm:

Wilson "Snowflake" Bentley, public domain. Courtesy Jericho Historical Society.

 Giant Snowflake S ♥38 ⟁13 ☺8 ↠0' ↟30' (hover)
{+2 +3 +0 +4 +0 -1}; [I] cold, poison; Sharp († miss by 5: 1d8 P)
Whirl Dash move, DEX 12 2d8 S, 𝕊 1d8 C (stop after first hit); Frost Shield Re: adj ally hit, -1d6 damage 

Giant snowflakes are CR 2 elementals. They're about 3 feet across, made of sharp spikes and plates of ice, and spin and twirl through the air, so fighting one is like sticking your hand into a lawnmower. If you're into gore, you could describe how the spinning outer bits go from almost invisibly translucent to a thick red ring after they draw blood. They're also bizarrely intelligent, and have one big eyeball in the center that stays in place as they spin.

They're great for summons, perhaps as a familiar for an advanced cryomancer, or they could be naturally occurring in any snowy environment. Since they have a reaction to protect an ally, they do well in groups. I'm using them as part of the army of ice elementals besieging my city, where they're the elite troops of the aerial division, above cockatrices as the low-level infantry.

With the first monster comes a dilemma about how to present them.  I have an ongoing quest to develop the densest, most bare-boned, functional stat block possible, and no doubt my ranting and rationale will become a post here in the near future. For now, I'll just explain how to read the one above, then reprint it in another, more typical format.

The first line has all the core stats: name, size (abbreviated: S for small, in this case), hit points (denoted with a heart), armor class (that little triangle thingy that looks a bit like a shield), and morale (smiley face, using 2d6 roll-under). Movement modes are also included, but only if they're different from the default; the horizontal arrow is regular walking movement (giant snowflakes are helpless if you can pin them to the ground), and the up-pointing arrow is fly speed.

The next lines are for traits: anything that isn't either core or an action. Here we have ability modifiers in the curly braces, in the usual order of STR, DEX, CON, INT, WIS, CHA. The [I] indicates immunities to cold and poison damage, and [R] and [V] would likewise indicate resistances and vulnerabilities. Then there's the Sharp trait: if a melee attack (dagger icon) misses by 5 or more, the attacker takes 1d8 piercing damage. Intuitively, this would apply to grappling as well.

The last line is for actions. The name of each action is bold, so it can be spotted at a glance, and its most common go-to action is underlined. The giant snowflake only has weird actions so it's harder to explain, a more typical one would look like this:

Icicle Spear +4 †↗20'/60' 1d6+2 P; Redirect Attack Re: targeted, adj Rime Soldier swaps

(from a Rime Captain, a reflavored goblin boss). After the name of the action is the to-hit bonus or save, any targeting information, then damage and other effects. The Rime captain has +4 to hit, its Icicle Spear is a melee (dagger icon) or ranged (up-right arrow) weapon attack with a 20'/60' range (5' range for melee attacks is the default), and if it hits it deals 1d6+2 piercing damage. Bludgeoning, piercing, and slashing are far too common and too long to write out every time, so they're abbreviated to B, P, and S. Since I have a lot of ice monsters, I also use C for cold.

The giant snowflake's Whirl Dash action is a little more complicated. The snowflake moves (up to its speed), and any creature's space it moves through must make a DC 12 Dexterity saving throw (DEX 12). Implied, but not stated, is that it can move through other creatures' spaces, since that's how these sorts of attacks usually work, and that it has to move in a straight line, since this is a sort of charge attack - but that part is technically optional. Next is the effect on a failed save (2d8 slashing damage), then the fancy 𝕊 to indicate what happens on a successful save: 1d8 cold damage. Lastly is a unique note for this creature: after it hits one target, it stops attacking, which is something players may be able to figure out and exploit.

Lastly, both creatures have a reaction, noted by Re:, followed by the condition being reacted to, followed by the response. The Rime captain can swap places with its soldiers when it's targeted by an attack, using them as meat shields, and the giant snowflake can interpose itself as a flying shield to reduce damage to an ally.

If all that was too much nonsense for you (and it's too much nonsense for me most of the time), here's the same monster in a more typical 5e stat block format:

Giant Snowflake

Small elemental, neutral evil

Armor Class 13

Hit Points 38

Speed 0 ft., fly 30 ft.

STR +2, DEX +3, CON +0, INT +4, WIS +0, CHA -1

Traits

Damage Immunities cold, poison

Condition Immunities poisoned, exhaustion

Senses passive Perception 10

CR 2

Sharp. When a creature touches the snowflake or misses it with a melee weapon attack by 5 or more, it takes 1d8 piercing damage.

Actions

Whirl Dash. The snowflake moves up to its speed in a straight line, during which it can move through other creatures' spaces with no penalty. Each creature whose space the snowflake enters must make a DC 12 Dexterity saving throw or take 2d8 slashing damage. On a success, the target takes half as much cold damage. The giant snowflake stops the first time a target fails its save.

Reaction: Frost Shield. When an ally adjacent to the giant snowflake takes damage, the snowflake can use its reaction to interpose itself as a shield. The damage taken is reduced by 1d6.