diff --git a/mappings/net/minecraft/util/collection/DataPool.mapping b/mappings/net/minecraft/util/collection/DataPool.mapping
new file mode 100644
index 0000000000..034fcdf07a
--- /dev/null
+++ b/mappings/net/minecraft/util/collection/DataPool.mapping
@@ -0,0 +1,12 @@
+CLASS net/minecraft/class_6005 net/minecraft/util/collection/DataPool
+	METHOD method_34971 builder ()Lnet/minecraft/class_6005$class_6006;
+	METHOD method_34972 createCodec (Lcom/mojang/serialization/Codec;)Lcom/mojang/serialization/Codec;
+		ARG 0 dataCodec
+	METHOD method_34973 getDataOrEmpty (Ljava/util/Random;)Ljava/util/Optional;
+		ARG 1 random
+	CLASS class_6006 Builder
+		FIELD field_29926 entries Lcom/google/common/collect/ImmutableList$Builder;
+		METHOD method_34974 build ()Lnet/minecraft/class_6005;
+		METHOD method_34975 add (Ljava/lang/Object;I)Lnet/minecraft/class_6005$class_6006;
+			ARG 1 object
+			ARG 2 weight
diff --git a/mappings/net/minecraft/util/collection/Pool.mapping b/mappings/net/minecraft/util/collection/Pool.mapping
new file mode 100644
index 0000000000..58a9d1d62e
--- /dev/null
+++ b/mappings/net/minecraft/util/collection/Pool.mapping
@@ -0,0 +1,16 @@
+CLASS net/minecraft/class_6012 net/minecraft/util/collection/Pool
+	FIELD field_29934 totalWeight I
+	FIELD field_29935 entries Lcom/google/common/collect/ImmutableList;
+	METHOD <init> (Ljava/util/List;)V
+		ARG 1 entries
+	METHOD method_34988 of (Ljava/util/List;)Lnet/minecraft/class_6012;
+		ARG 0 entries
+	METHOD method_34989 of ([Lnet/minecraft/class_6008;)Lnet/minecraft/class_6012;
+		ARG 0 entries
+	METHOD method_34990 empty ()Lnet/minecraft/class_6012;
+	METHOD method_34991 createCodec (Lcom/mojang/serialization/Codec;)Lcom/mojang/serialization/Codec;
+		ARG 0 entryCodec
+	METHOD method_34992 getOrEmpty (Ljava/util/Random;)Ljava/util/Optional;
+		ARG 1 random
+	METHOD method_34993 isEmpty ()Z
+	METHOD method_34994 getEntries ()Ljava/util/List;
diff --git a/mappings/net/minecraft/util/collection/Weight.mapping b/mappings/net/minecraft/util/collection/Weight.mapping
new file mode 100644
index 0000000000..70d161c97d
--- /dev/null
+++ b/mappings/net/minecraft/util/collection/Weight.mapping
@@ -0,0 +1,14 @@
+CLASS net/minecraft/class_6007 net/minecraft/util/collection/Weight
+	FIELD field_29927 CODEC Lcom/mojang/serialization/Codec;
+	FIELD field_29928 DEFAULT Lnet/minecraft/class_6007;
+	FIELD field_29929 LOGGER Lorg/apache/logging/log4j/Logger;
+	FIELD field_29930 value I
+	METHOD <init> (I)V
+		ARG 1 weight
+	METHOD equals (Ljava/lang/Object;)Z
+		ARG 1 o
+	METHOD method_34976 getValue ()I
+	METHOD method_34977 of (I)Lnet/minecraft/class_6007;
+		ARG 0 weight
+	METHOD method_34978 validate (I)V
+		ARG 0 weight
diff --git a/mappings/net/minecraft/util/collection/Weighted.mapping b/mappings/net/minecraft/util/collection/Weighted.mapping
new file mode 100644
index 0000000000..42c0f26c16
--- /dev/null
+++ b/mappings/net/minecraft/util/collection/Weighted.mapping
@@ -0,0 +1,20 @@
+CLASS net/minecraft/class_6008 net/minecraft/util/collection/Weighted
+	METHOD method_34979 getWeight ()Lnet/minecraft/class_6007;
+	METHOD method_34980 of (Ljava/lang/Object;I)Lnet/minecraft/class_6008$class_6010;
+		ARG 0 data
+		ARG 1 weight
+	CLASS class_6009 Absent
+		FIELD field_29931 weight Lnet/minecraft/class_6007;
+		METHOD <init> (I)V
+			ARG 1 weight
+		METHOD <init> (Lnet/minecraft/class_6007;)V
+			ARG 1 weight
+	CLASS class_6010 Present
+		FIELD field_29932 data Ljava/lang/Object;
+		FIELD field_29933 weight Lnet/minecraft/class_6007;
+		METHOD <init> (Ljava/lang/Object;Lnet/minecraft/class_6007;)V
+			ARG 1 data
+			ARG 2 weight
+		METHOD method_34981 createCodec (Lcom/mojang/serialization/Codec;)Lcom/mojang/serialization/Codec;
+			ARG 0 dataCodec
+		METHOD method_34983 getData ()Ljava/lang/Object;
diff --git a/mappings/net/minecraft/util/collection/Weighting.mapping b/mappings/net/minecraft/util/collection/Weighting.mapping
new file mode 100644
index 0000000000..03b15f2be2
--- /dev/null
+++ b/mappings/net/minecraft/util/collection/Weighting.mapping
@@ -0,0 +1,13 @@
+CLASS net/minecraft/class_6011 net/minecraft/util/collection/Weighting
+	METHOD method_34984 getWeightSum (Ljava/util/List;)I
+		ARG 0 pool
+	METHOD method_34985 getAt (Ljava/util/List;I)Ljava/util/Optional;
+		ARG 0 pool
+		ARG 1 totalWeight
+	METHOD method_34986 getRandom (Ljava/util/Random;Ljava/util/List;)Ljava/util/Optional;
+		ARG 0 random
+		ARG 1 pool
+	METHOD method_34987 getRandom (Ljava/util/Random;Ljava/util/List;I)Ljava/util/Optional;
+		ARG 0 random
+		ARG 1 pool
+		ARG 2 totalWeight