diff --git a/dist/extension.zip b/dist/extension.zip
index ed80af7..81686b7 100644
Binary files a/dist/extension.zip and b/dist/extension.zip differ
diff --git a/dist/extension/birb.js b/dist/extension/birb.js
index a38d411..43ca98d 100644
--- a/dist/extension/birb.js
+++ b/dist/extension/birb.js
@@ -618,13 +618,12 @@
 		"#373737": PALETTE.FEATHER_SPINE,
 	};
 
-	/**
-	 * @type {Record<string, string>} 
-	 */
-	const RARITY = {
+	const RARITY = Object.freeze(/** @type {const} */ ({
 		FAMILIAR: "familiar",
 		UNCOMMON: "uncommon"
-	};
+	}));
+
+	/** @typedef {typeof RARITY[keyof typeof RARITY]} Rarity */
 
 	class BirdType {
 		/**
@@ -632,7 +631,7 @@
 		 * @param {string} description
 		 * @param {Record<string, string>} colors
 		 * @param {string[]} [tags]
-		 * @param {string} [rarity]
+		 * @param {Rarity} [rarity]
 		 */
 		constructor(name, description, colors, tags = [], rarity = RARITY.FAMILIAR) {
 			this.name = name;
@@ -665,6 +664,7 @@
 			/** @type {Record<string, string>} */
 			this.colors = { ...defaultColors, ...colors, [PALETTE.THEME_HIGHLIGHT]: colors[PALETTE.THEME_HIGHLIGHT] ?? colors.hood ?? colors.face };
 			this.tags = tags;
+			/** @type {Rarity} */
 			this.rarity = rarity;
 		}
 	}
@@ -2398,6 +2398,7 @@
 	const HOP_CHANCE = 1 / (60 * 2.5); // Every 2.5 seconds
 	const FOCUS_SWITCH_CHANCE = 1 / (60 * 20); // Every 20 seconds
 	const FEATHER_CHANCE = 1 / (60 * 60 * 60 * 2); // Every 2 hours
+	const UNCOMMON_FEATHER_CHANCE = 0.1; // 10% of feathers are uncommon
 	const HAT_CHANCE = 1 / (60 * 60 * 25); // Every 25 minutes
 
 	// Feathers
@@ -2849,7 +2850,8 @@
 			if (document.querySelector("#" + FEATHER_ID)) {
 				return;
 			}
-			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species));
+			const rarity = Math.random() < UNCOMMON_FEATHER_CHANCE ? RARITY.UNCOMMON : RARITY.FAMILIAR;
+			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species) && SPECIES[species].rarity === rarity);
 			if (speciesToUnlock.length === 0) {
 				// No more species to unlock
 				return;
diff --git a/dist/obsidian/main.js b/dist/obsidian/main.js
index db1442a..96224ee 100644
--- a/dist/obsidian/main.js
+++ b/dist/obsidian/main.js
@@ -623,13 +623,12 @@ module.exports = class PocketBird extends Plugin {
 		"#373737": PALETTE.FEATHER_SPINE,
 	};
 
-	/**
-	 * @type {Record<string, string>} 
-	 */
-	const RARITY = {
+	const RARITY = Object.freeze(/** @type {const} */ ({
 		FAMILIAR: "familiar",
 		UNCOMMON: "uncommon"
-	};
+	}));
+
+	/** @typedef {typeof RARITY[keyof typeof RARITY]} Rarity */
 
 	class BirdType {
 		/**
@@ -637,7 +636,7 @@ module.exports = class PocketBird extends Plugin {
 		 * @param {string} description
 		 * @param {Record<string, string>} colors
 		 * @param {string[]} [tags]
-		 * @param {string} [rarity]
+		 * @param {Rarity} [rarity]
 		 */
 		constructor(name, description, colors, tags = [], rarity = RARITY.FAMILIAR) {
 			this.name = name;
@@ -670,6 +669,7 @@ module.exports = class PocketBird extends Plugin {
 			/** @type {Record<string, string>} */
 			this.colors = { ...defaultColors, ...colors, [PALETTE.THEME_HIGHLIGHT]: colors[PALETTE.THEME_HIGHLIGHT] ?? colors.hood ?? colors.face };
 			this.tags = tags;
+			/** @type {Rarity} */
 			this.rarity = rarity;
 		}
 	}
@@ -2431,6 +2431,7 @@ module.exports = class PocketBird extends Plugin {
 	const HOP_CHANCE = 1 / (60 * 2.5); // Every 2.5 seconds
 	const FOCUS_SWITCH_CHANCE = 1 / (60 * 20); // Every 20 seconds
 	const FEATHER_CHANCE = 1 / (60 * 60 * 60 * 2); // Every 2 hours
+	const UNCOMMON_FEATHER_CHANCE = 0.1; // 10% of feathers are uncommon
 	const HAT_CHANCE = 1 / (60 * 60 * 25); // Every 25 minutes
 
 	// Feathers
@@ -2882,7 +2883,8 @@ module.exports = class PocketBird extends Plugin {
 			if (document.querySelector("#" + FEATHER_ID)) {
 				return;
 			}
-			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species));
+			const rarity = Math.random() < UNCOMMON_FEATHER_CHANCE ? RARITY.UNCOMMON : RARITY.FAMILIAR;
+			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species) && SPECIES[species].rarity === rarity);
 			if (speciesToUnlock.length === 0) {
 				// No more species to unlock
 				return;
diff --git a/dist/userscript/birb.user.js b/dist/userscript/birb.user.js
index 561386e..38d3266 100644
--- a/dist/userscript/birb.user.js
+++ b/dist/userscript/birb.user.js
@@ -632,13 +632,12 @@
 		"#373737": PALETTE.FEATHER_SPINE,
 	};
 
-	/**
-	 * @type {Record<string, string>} 
-	 */
-	const RARITY = {
+	const RARITY = Object.freeze(/** @type {const} */ ({
 		FAMILIAR: "familiar",
 		UNCOMMON: "uncommon"
-	};
+	}));
+
+	/** @typedef {typeof RARITY[keyof typeof RARITY]} Rarity */
 
 	class BirdType {
 		/**
@@ -646,7 +645,7 @@
 		 * @param {string} description
 		 * @param {Record<string, string>} colors
 		 * @param {string[]} [tags]
-		 * @param {string} [rarity]
+		 * @param {Rarity} [rarity]
 		 */
 		constructor(name, description, colors, tags = [], rarity = RARITY.FAMILIAR) {
 			this.name = name;
@@ -679,6 +678,7 @@
 			/** @type {Record<string, string>} */
 			this.colors = { ...defaultColors, ...colors, [PALETTE.THEME_HIGHLIGHT]: colors[PALETTE.THEME_HIGHLIGHT] ?? colors.hood ?? colors.face };
 			this.tags = tags;
+			/** @type {Rarity} */
 			this.rarity = rarity;
 		}
 	}
@@ -2393,6 +2393,7 @@
 	const HOP_CHANCE = 1 / (60 * 2.5); // Every 2.5 seconds
 	const FOCUS_SWITCH_CHANCE = 1 / (60 * 20); // Every 20 seconds
 	const FEATHER_CHANCE = 1 / (60 * 60 * 60 * 2); // Every 2 hours
+	const UNCOMMON_FEATHER_CHANCE = 0.1; // 10% of feathers are uncommon
 	const HAT_CHANCE = 1 / (60 * 60 * 25); // Every 25 minutes
 
 	// Feathers
@@ -2844,7 +2845,8 @@
 			if (document.querySelector("#" + FEATHER_ID)) {
 				return;
 			}
-			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species));
+			const rarity = Math.random() < UNCOMMON_FEATHER_CHANCE ? RARITY.UNCOMMON : RARITY.FAMILIAR;
+			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species) && SPECIES[species].rarity === rarity);
 			if (speciesToUnlock.length === 0) {
 				// No more species to unlock
 				return;
diff --git a/dist/web/birb.embed.js b/dist/web/birb.embed.js
index a7e93d5..08358cd 100644
--- a/dist/web/birb.embed.js
+++ b/dist/web/birb.embed.js
@@ -618,13 +618,12 @@
 		"#373737": PALETTE.FEATHER_SPINE,
 	};
 
-	/**
-	 * @type {Record<string, string>} 
-	 */
-	const RARITY = {
+	const RARITY = Object.freeze(/** @type {const} */ ({
 		FAMILIAR: "familiar",
 		UNCOMMON: "uncommon"
-	};
+	}));
+
+	/** @typedef {typeof RARITY[keyof typeof RARITY]} Rarity */
 
 	class BirdType {
 		/**
@@ -632,7 +631,7 @@
 		 * @param {string} description
 		 * @param {Record<string, string>} colors
 		 * @param {string[]} [tags]
-		 * @param {string} [rarity]
+		 * @param {Rarity} [rarity]
 		 */
 		constructor(name, description, colors, tags = [], rarity = RARITY.FAMILIAR) {
 			this.name = name;
@@ -665,6 +664,7 @@
 			/** @type {Record<string, string>} */
 			this.colors = { ...defaultColors, ...colors, [PALETTE.THEME_HIGHLIGHT]: colors[PALETTE.THEME_HIGHLIGHT] ?? colors.hood ?? colors.face };
 			this.tags = tags;
+			/** @type {Rarity} */
 			this.rarity = rarity;
 		}
 	}
@@ -2373,6 +2373,7 @@
 	const HOP_CHANCE = 1 / (60 * 2.5); // Every 2.5 seconds
 	const FOCUS_SWITCH_CHANCE = 1 / (60 * 20); // Every 20 seconds
 	const FEATHER_CHANCE = 1 / (60 * 60 * 60 * 2); // Every 2 hours
+	const UNCOMMON_FEATHER_CHANCE = 0.1; // 10% of feathers are uncommon
 	const HAT_CHANCE = 1 / (60 * 60 * 25); // Every 25 minutes
 
 	// Feathers
@@ -2824,7 +2825,8 @@
 			if (document.querySelector("#" + FEATHER_ID)) {
 				return;
 			}
-			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species));
+			const rarity = Math.random() < UNCOMMON_FEATHER_CHANCE ? RARITY.UNCOMMON : RARITY.FAMILIAR;
+			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species) && SPECIES[species].rarity === rarity);
 			if (speciesToUnlock.length === 0) {
 				// No more species to unlock
 				return;
diff --git a/dist/web/birb.js b/dist/web/birb.js
index a7e93d5..08358cd 100644
--- a/dist/web/birb.js
+++ b/dist/web/birb.js
@@ -618,13 +618,12 @@
 		"#373737": PALETTE.FEATHER_SPINE,
 	};
 
-	/**
-	 * @type {Record<string, string>} 
-	 */
-	const RARITY = {
+	const RARITY = Object.freeze(/** @type {const} */ ({
 		FAMILIAR: "familiar",
 		UNCOMMON: "uncommon"
-	};
+	}));
+
+	/** @typedef {typeof RARITY[keyof typeof RARITY]} Rarity */
 
 	class BirdType {
 		/**
@@ -632,7 +631,7 @@
 		 * @param {string} description
 		 * @param {Record<string, string>} colors
 		 * @param {string[]} [tags]
-		 * @param {string} [rarity]
+		 * @param {Rarity} [rarity]
 		 */
 		constructor(name, description, colors, tags = [], rarity = RARITY.FAMILIAR) {
 			this.name = name;
@@ -665,6 +664,7 @@
 			/** @type {Record<string, string>} */
 			this.colors = { ...defaultColors, ...colors, [PALETTE.THEME_HIGHLIGHT]: colors[PALETTE.THEME_HIGHLIGHT] ?? colors.hood ?? colors.face };
 			this.tags = tags;
+			/** @type {Rarity} */
 			this.rarity = rarity;
 		}
 	}
@@ -2373,6 +2373,7 @@
 	const HOP_CHANCE = 1 / (60 * 2.5); // Every 2.5 seconds
 	const FOCUS_SWITCH_CHANCE = 1 / (60 * 20); // Every 20 seconds
 	const FEATHER_CHANCE = 1 / (60 * 60 * 60 * 2); // Every 2 hours
+	const UNCOMMON_FEATHER_CHANCE = 0.1; // 10% of feathers are uncommon
 	const HAT_CHANCE = 1 / (60 * 60 * 25); // Every 25 minutes
 
 	// Feathers
@@ -2824,7 +2825,8 @@
 			if (document.querySelector("#" + FEATHER_ID)) {
 				return;
 			}
-			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species));
+			const rarity = Math.random() < UNCOMMON_FEATHER_CHANCE ? RARITY.UNCOMMON : RARITY.FAMILIAR;
+			const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species) && SPECIES[species].rarity === rarity);
 			if (speciesToUnlock.length === 0) {
 				// No more species to unlock
 				return;
diff --git a/src/animation/sprites.js b/src/animation/sprites.js
index 72e7774..2e03648 100644
--- a/src/animation/sprites.js
+++ b/src/animation/sprites.js
@@ -98,13 +98,12 @@ export const DEFAULT_COLOR_OVERRIDES = {
 	[PALETTE.WING_SPOTS]: PALETTE.WING,
 };
 
-/**
- * @type {Record<string, string>} 
- */
-export const RARITY = {
+export const RARITY = Object.freeze(/** @type {const} */ ({
 	FAMILIAR: "familiar",
 	UNCOMMON: "uncommon"
-}
+}));
+
+/** @typedef {typeof RARITY[keyof typeof RARITY]} Rarity */
 
 export class BirdType {
 	/**
@@ -112,7 +111,7 @@ export class BirdType {
 	 * @param {string} description
 	 * @param {Record<string, string>} colors
 	 * @param {string[]} [tags]
-	 * @param {string} [rarity]
+	 * @param {Rarity} [rarity]
 	 */
 	constructor(name, description, colors, tags = [], rarity = RARITY.FAMILIAR) {
 		this.name = name;
@@ -145,6 +144,7 @@ export class BirdType {
 		/** @type {Record<string, string>} */
 		this.colors = { ...defaultColors, ...colors, [PALETTE.THEME_HIGHLIGHT]: colors[PALETTE.THEME_HIGHLIGHT] ?? colors.hood ?? colors.face };
 		this.tags = tags;
+		/** @type {Rarity} */
 		this.rarity = rarity;
 	}
 }
diff --git a/src/application.js b/src/application.js
index 4c8736a..46755ed 100644
--- a/src/application.js
+++ b/src/application.js
@@ -110,6 +110,7 @@ const HOP_DELAY = 500;
 const HOP_CHANCE = 1 / (60 * 2.5); // Every 2.5 seconds
 const FOCUS_SWITCH_CHANCE = 1 / (60 * 20); // Every 20 seconds
 const FEATHER_CHANCE = 1 / (60 * 60 * 60 * 2); // Every 2 hours
+const UNCOMMON_FEATHER_CHANCE = 0.1; // 10% of feathers are uncommon
 const HAT_CHANCE = 1 / (60 * 60 * 25); // Every 25 minutes
 
 // Feathers
@@ -564,7 +565,8 @@ function startApplication(birbPixels, featherPixels, hatsPixels) {
 		if (document.querySelector("#" + FEATHER_ID)) {
 			return;
 		}
-		const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species));
+		const rarity = Math.random() < UNCOMMON_FEATHER_CHANCE ? RARITY.UNCOMMON : RARITY.FAMILIAR;
+		const speciesToUnlock = Object.keys(SPECIES).filter((species) => !unlockedSpecies.includes(species) && SPECIES[species].rarity === rarity);
 		if (speciesToUnlock.length === 0) {
 			// No more species to unlock
 			return;