diff --git a/mappings/net/minecraft/entity/Mount.mapping b/mappings/net/minecraft/entity/Mount.mapping
new file mode 100644
index 0000000000..1b7406b7f4
--- /dev/null
+++ b/mappings/net/minecraft/entity/Mount.mapping
@@ -0,0 +1 @@
+CLASS net/minecraft/class_6026 net/minecraft/entity/Mount
diff --git a/mappings/net/minecraft/util/HeapDumping.mapping b/mappings/net/minecraft/util/HeapDumping.mapping
new file mode 100644
index 0000000000..474d21673f
--- /dev/null
+++ b/mappings/net/minecraft/util/HeapDumping.mapping
@@ -0,0 +1,16 @@
+CLASS net/minecraft/class_5995 net/minecraft/util/HeapDumping
+	COMMENT A heap-dumping (dumps all object data in a JVM) utility using
+	COMMENT {@link HotSpotDiagnosticMXBean} from the Java Management Extensions API.
+	FIELD field_29840 HOTSPOT_DIAGNOSTIC_MXBEAN_NAME Ljava/lang/String;
+		COMMENT String representation of the {@code ObjectName} for the {@link HotSpotDiagnosticMXBean}.
+	FIELD field_29841 bean Lcom/sun/management/HotSpotDiagnosticMXBean;
+	METHOD method_34934 getBean ()Lcom/sun/management/HotSpotDiagnosticMXBean;
+	METHOD method_34935 dump (Ljava/lang/String;Z)V
+		COMMENT Dumps the heap to the {@code outputFile} file in the same format as the hprof
+		COMMENT heap dump.
+		COMMENT
+		COMMENT @see HotSpotDiagnosticMXBean#dumpHeap(String, boolean)
+		ARG 0 outputFile
+			COMMENT the system-dependent file name
+		ARG 1 live
+			COMMENT if {@code true} dump only live objects, i.e. objects that are reachable from others
diff --git a/mappings/net/minecraft/util/thread/GroupAssigningThreadFactory.mapping b/mappings/net/minecraft/util/thread/GroupAssigningThreadFactory.mapping
new file mode 100644
index 0000000000..cb41d0bb7e
--- /dev/null
+++ b/mappings/net/minecraft/util/thread/GroupAssigningThreadFactory.mapping
@@ -0,0 +1,13 @@
+CLASS net/minecraft/class_6014 net/minecraft/util/thread/GroupAssigningThreadFactory
+	COMMENT A custom thread factory that assigns each created thread to the group of the
+	COMMENT system security manager or the factory-creating thread (when the security
+	COMMENT manager does not exist). Otherwise, it behaves much like the thread creation
+	COMMENT logic in {@link net.minecraft.util.Util#createIoWorker()}.
+	FIELD field_29936 LOGGER Lorg/apache/logging/log4j/Logger;
+	FIELD field_29937 group Ljava/lang/ThreadGroup;
+	FIELD field_29938 nextIndex Ljava/util/concurrent/atomic/AtomicInteger;
+	FIELD field_29939 prefix Ljava/lang/String;
+	METHOD <init> (Ljava/lang/String;)V
+		ARG 1 name
+	METHOD newThread (Ljava/lang/Runnable;)Ljava/lang/Thread;
+		ARG 1 r