Monster Origins

A Minecraft 1.20.1 / Fabric addon for Origins that adds four origins: Arachne (a humanoid spider), Medusa (a gorgon), Harpy (a storm wind bird woman), and Mermaid (a singer of the deep). Each one plays completely differently: a fragile fast assassin, a tanky bruiser, an aerial skirmisher, and aquatic support with crowd control.

Arachne

• Carnivore only diet, can climb any surface (1.65x normal climb speed), traverses and crafts cobwebs freely. Immune to poison.
• Dangerous creatures glow with an outline once spotted, for as long as you can see them.
• About 85% of normal height and width (via Pehkui).
• Attacks poison the target for 10 seconds (undead immune, 5s cooldown).
• Every arthropod (spider, cave spider, silverfish, endermite) is friendly until you attack it.
• Night vision. 6 hearts of health, a small amount of natural armor.
• Rappel (double tap space, same as Origins Minus's Weaver origin): pull yourself upward on a strand of web. Only works indoors, under a ceiling or overhang.
• Scuttle (secondary key, unbound by default): a burst of Speed IV for 4 seconds, at the cost of burning through food much faster while it's active. 15 second cooldown.
• Can't use a shield.
• Falls under 10 blocks deal no fall damage at all; falls of 10 blocks or more deal only 52% of normal damage (matching Feather Falling IV).
• Weakened while touching water, a spider out of its element.
• Takes 50% more damage from fire: brittle, dry, and flammable.
• Naturally produces 3 silk every 20 minutes.
• Quickness: +35% base movement speed, well past a token buff. Spiders are quick for their size. A flat attribute bonus, not a potion effect.
• Golden Spider Eye: a new food item, the carnivore diet equivalent of a golden apple (which Arachne can't eat since apples aren't meat). Same crafting cost (8 gold ingots around the center item) and the same buff (Regeneration II for 5s, Absorption I for 2 minutes), just built around a spider eye instead of an apple.
• Silk: a new crafting material (3 string makes 1 silk), craftable by anyone but thematically Arachne's own, used in the Silk Net Shooter's own recipe (see Weapons below).

Medusa

• Carnivore only diet. 12 hearts of health, 8 armor points: a bruiser, not a glass cannon.
• Petrifying Bite: unarmed strikes, or hits with the Petrifying Trident, briefly turn the target to stone (3 seconds of heavy Slowness, Mining Fatigue, Blindness, and Darkness). 5 second cooldown.
• Stone Cursed: immune to Slowness and Mining Fatigue. Her own curse can't touch her.
• Immune to fall damage.
• Permanent night vision, a monster of the dark.
• Stone Gaze: hostile creatures (and iron golems) that wander within 6 blocks are turned briefly to stone, once every 8 seconds per creature.
• Stone Gaze Burst (secondary key, unbound by default): petrifies every hostile creature (plus villagers and iron golems) within 10 blocks for 5 seconds, with a boulder impact sound. 30 second cooldown.
• Naturally sheds 6 Medusa Scales every 10 minutes (used in the Serpent Aegis's own recipe).
• Iron golems see through her and attack on sight; villagers refuse to trade with her and flinch away in fear whenever she gets close.

Harpy

• Carnivore only diet. 8 hearts of health, light hollow bones. Can't use a shield.
• Featherfall: never takes fall damage, no matter how far she drops.
• Wings: true flight, always. No elytra item needed. Holding forward while flying gradually builds speed up to a cap of 300% of normal elytra speed (a quick initial jump, tapering off as you approach the cap); holding backward actively brakes; letting go of both lets speed drift back down on its own. Gliding at a steady speed is free; actively gaining speed costs hunger, so flight has a real cost on long trips.
• Talons: bare handed strikes deal 4 extra hearts of damage and inflict Bleed for 10 seconds (undead immune), a status effect added by this mod that ticks like Poison but, unlike Poison, can kill. The faster she's flying when a hit (thrown or melee) lands, the more bonus damage on top, up to +7 extra hearts at full flight speed.
• 85% of normal height and width (via Pehkui).
• Hardy Stomach: raw meat and rotten flesh are perfectly safe to eat, no Hunger effect, just a brief burst of Saturation instead.
• Takes 50% more damage from fire: hollow bones and feathers catch fast.
• Naturally sheds 3 feathers every 10 minutes (used in the Storm Trident's own recipe).

Mermaid

• Carnivore only diet. 90% of normal height and width (via Pehkui).
• Fully at home in the water: breathes, sees, and swims underwater with no trouble, and mines at full (Aqua Affinity) speed while submerged.
• Landbound: can stay out of water (rain counts as wet too) for 5 minutes at a time before starting to suffocate. A HUD bar shows how much of that time is left, once any of it has passed.
• Swift Current: much higher swimming speed, and turns/steers as responsively as walking on land does, not the sluggish drift vanilla swimming normally has.
• Landlegs: 0.8x normal walking speed. She belongs in the water, not on land.
• Mermaid's Call (primary key, unbound by default): a real singing sound effect. Everyone nearby, including herself, is bathed in Saturation and Regeneration, while hostile creatures caught in it are slowed, blinded, weakened, and charmed into leaving everyone alone entirely for the duration. 4 second duration, 20 second cooldown.
• Riptide (secondary key, unbound by default): a quick forward burst, the same push strength as a real Riptide III enchantment, for a fast way to get moving. 5 second cooldown.
• Every sea creature is friendly unless attacked first, including Drowned and Guardians, not just the obviously passive fish.
• Mining a live coral block bare handed (or with any tool lacking Silk Touch) gets the live block instead of vanilla's usual dead coral fallback.
• Killing a fish (Cod, Salmon, Pufferfish, or Tropical Fish) has a 5% chance to additionally drop a Prismarine Shard.
• Takes 50% more damage from fire: dries out fast.
• No water breathing bubble particles while it's active, just the effect, not the visual spam.

Weapons

• Every origin gets a themed craftable weapon. Anyone can craft or swing either one, but the bonus on hit effect only triggers for the matching origin. Each is its own origin's signature weapon, not generically useful loot:
• Fang: a light, fast dagger with a real dagger shaped icon: a shortened diagonal blade built the same way vanilla's own sword icons are (alternating light/mid tones, a dark outline, a distinct guard), not a recolored sword, in three tiers, each with its own blade and grip color. Poisons on every hit, undead excluded, Arachne only. Every tier's tooltip spells out exactly what it does and who it's for.

1. Fang (base): iron tier stats, Poison only. Crafted from a spider eye, an iron ingot, and a stick.
2. Venomfang: diamond tier (6 attack damage), adds Bleed. Upgraded on a crafting table from a Fang, a diamond, and a Golden Spider Eye.
3. Widowfang: netherite tier (7 attack damage), adds Wither on top of Poison and Bleed. Upgraded on a smithing table from a Venomfang, a netherite ingot, and another Golden Spider Eye, matching vanilla's own Diamond to Netherite upgrade convention rather than a plain crafting recipe.

• Silk Net Shooter: a throwable weapon (100 uses) that traps its target in cobwebs and heavy Slowness on a hit. Arachne only. Crafted from silk and sticks.

• Serpent Aegis: a real off hand shield (3000 durability). Blocking a melee attack slows the attacker and reflects half the blocked damage back at them; nearby allies take half damage from anything while she's actively blocking with it. Immune to Ghast fireballs. Medusa only. Crafted from Medusa Scales and iron ingots.

• Petrifying Trident: a reskinned vanilla trident (same stats and behavior: throwable, riptide) that briefly petrifies whatever it hits (a lighter dose than Medusa's own Petrifying Bite). Medusa only. Crafted from stone and iron ingots.

• Storm Trident: A real 3D modeled throwing trident built on vanilla's actual Trident geometry, lighter and faster swinging than a plain vanilla trident. Causes Bleed on hit (undead excluded), whether thrown or swung, plus flight speed scaled bonus damage. A thrown hit that lands also calls down a real lightning bolt with area damage, on a 30 second cooldown. Harpy only. Crafted from a diamond, an iron ingot, and a Harpy Feather.

• Living Coral Trident: Mermaid's own late game weapon (3500 durability), also built on real vanilla Trident geometry. Symbiosis (small hunger restore on every hit), Barbed Tip (bonus damage against a target currently in water), Bleeding Current (Bleed on hit while she's in water), and +1 block reach while held. Mermaid only. Crafted from prismarine shards, a fire coral block, and a diamond.

All origin gated weapons spell this out directly in their tooltip, not just in the README. No player should have to guess whose weapon they're holding.

It's also written as a worked, documented example of a data driven pattern for adding more origins. See TEMPLATE.MD. Medusa is the second worked example (the first was Arachne); Harpy is the third, and the first origin in this mod that genuinely needs custom Java beyond a single mixin: a new status effect (Bleed) and a custom Apoli action type (Scream's forward cone knockback), since neither has any data driven path. See CLAUDE.md for exactly why.

Requirements (to play)

Drop these into your mods/ folder (all for 1.20.1 Fabric):

• Fabric API (0.92.11+1.20.1 or newer)
• Origins (1.10.2+mc.1.20.1 or newer)
• Origins Minus (2.4.0+1.20 or newer)
• Pehkui (3.8.3+1.14.4-1.21 or newer)

Credits & licenses

Built against Origins and Origins Minus by their respective authors. This mod is an addon for their work, not affiliated with them. This mod's own code is available under CC0 (the Fabric template's license). Harpy's Scream sound is a real recording used under CC BY SA 4.0. See CREDITS.MD for full attribution.