diff --git a/tests/browser/test/mutator_test.js b/tests/browser/test/mutator_test.js
new file mode 100644
index 00000000000..f4f4b20154c
--- /dev/null
+++ b/tests/browser/test/mutator_test.js
@@ -0,0 +1,96 @@
+/**
+ * @license
+ * Copyright 2023 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @fileoverview Node.js script to run Automated tests in Chrome, via webdriver.
+ */
+
+const chai = require('chai');
+const {
+  testSetup,
+  testFileLocations,
+  connect,
+  switchRTL,
+  dragBlockTypeFromFlyout,
+  getSelectedBlockId,
+  screenDirection,
+} = require('./test_setup');
+
+suite('This tests mutating a Blockly block', function (done) {
+  // Setting timeout to unlimited as the webdriver takes a longer time to run than most mocha test
+  this.timeout(0);
+
+  // Setup Selenium for all of the tests
+  suiteSetup(async function () {
+    this.browser = await testSetup(testFileLocations.PLAYGROUND);
+  });
+
+  test('This test mutating a block creates more inputs', async function () {
+    await testingMutator(this.browser, screenDirection.LTR);
+  });
+});
+
+async function testingMutator(browser, delta) {
+  // Drag out print from flyout.
+  const controlIfFlyout = await dragBlockTypeFromFlyout(
+    browser,
+    'Logic',
+    'controls_if',
+    delta * 50,
+    50,
+  );
+  // Click on the mutator and drag out else ig block
+  const mutatorWheel = await browser.$(
+    '#blocklyDiv > div > svg.blocklySvg > g > g.blocklyBlockCanvas > g.blocklyDraggable.blocklySelected > g.blocklyIconGroup',
+  );
+  await mutatorWheel.click();
+  await browser.pause(100);
+  const elseIfFlyout = await browser.$(
+    '#blocklyDiv > div > svg.blocklySvg > g > g.blocklyBubbleCanvas > g > g:nth-child(2) > svg:nth-child(1) > g > g.blocklyFlyout > g > g.blocklyBlockCanvas > g:nth-child(3)',
+  );
+  await elseIfFlyout.dragAndDrop({x: delta * 50, y: 42});
+  await browser.pause(100);
+
+  await browser.pause(100);
+  // Get the ids for the blocks in the mutator
+  const blockIds = await browser.execute(() => {
+    const mutatorBlock = Blockly.getMainWorkspace().getAllBlocks()[0];
+    // Adding the first element in the array is the original block id, the second is the first mutator block, and the third is the second mutator block
+    const blockIds = [
+      mutatorBlock.id,
+      mutatorBlock.mutator.getWorkspace().getAllBlocks()[0].id,
+      mutatorBlock.mutator.getWorkspace().getAllBlocks()[1].id,
+    ];
+    return blockIds;
+  });
+
+  // The flyout block and the workspace block have the same id, so to get around that I pass in the selector to the connect function
+  const dragBlockSelector = await browser.$(
+    '#blocklyDiv > div > svg.blocklySvg > g > g.blocklyBubbleCanvas > g > g:nth-child(2) > svg:nth-child(1) > g > g.blocklyBlockCanvas > g.blocklyDraggable',
+  );
+  // For some reason this needs a lot more time
+  await browser.pause(2000);
+  // Connect the mutator blocks
+  await connect(
+    browser,
+    blockIds[2],
+    'PREVIOUS',
+    blockIds[1],
+    'NEXT',
+    blockIds[0],
+    dragBlockSelector,
+  );
+  await browser.pause(200);
+
+  // Get the ids for block after mutating
+  const afterInputs = await browser.execute(() => {
+    const afterInputs =
+      Blockly.getMainWorkspace().getAllBlocks()[0].inputList.length;
+    return afterInputs;
+  });
+
+  chai.assert.equal(afterInputs, 4);
+}
diff --git a/tests/browser/test/test_setup.js b/tests/browser/test/test_setup.js
index 386c94b4df8..9376db984f2 100644
--- a/tests/browser/test/test_setup.js
+++ b/tests/browser/test/test_setup.js
@@ -220,13 +220,27 @@ async function getBlockTypeFromWorkspace(browser, blockType, position) {
  * @param connectionName Which connection to return. An input name to
  *     get a value or statement connection, and otherwise the type of
  *     the connection.
+ * @param mutatorBlockId The block that holds the mutator icon or null if the target block is on the main workspace
  * @return A Promise that resolves to the location of the specific
  *     connection in screen coordinates.
  */
-async function getLocationOfBlockConnection(browser, id, connectionName) {
+async function getLocationOfBlockConnection(
+  browser,
+  id,
+  connectionName,
+  mutatorBlockId,
+) {
   return await browser.execute(
-    (id, connectionName) => {
-      const block = Blockly.getMainWorkspace().getBlockById(id);
+    (id, connectionName, mutatorBlockId) => {
+      let block;
+      if (mutatorBlockId) {
+        block = Blockly.getMainWorkspace()
+          .getBlockById(mutatorBlockId)
+          .mutator.getWorkspace()
+          .getBlockById(id);
+      } else {
+        block = Blockly.getMainWorkspace().getBlockById(id);
+      }
 
       let connection;
       switch (connectionName) {
@@ -255,6 +269,7 @@ async function getLocationOfBlockConnection(browser, id, connectionName) {
     },
     id,
     connectionName,
+    mutatorBlockId,
   );
 }
 
@@ -266,6 +281,8 @@ async function getLocationOfBlockConnection(browser, id, connectionName) {
  * @param draggedConnection The active connection on the block being dragged.
  * @param targetBlock The block to drag to.
  * @param targetConnection The connection to connect to on the target block.
+ * @param mutatorBlockId The block that holds the mutator icon or null if the target block is on the main workspace
+ * @param dragBlockSelector The selector of the block to drag
  * @return A Promise that resolves when the actions are completed.
  */
 async function connect(
@@ -274,24 +291,47 @@ async function connect(
   draggedConnection,
   targetBlock,
   targetConnection,
+  mutatorBlockId,
+  dragBlockSelector,
 ) {
-  const draggedLocation = await getLocationOfBlockConnection(
-    browser,
-    draggedBlock.id,
-    draggedConnection,
-  );
-  const targetLocation = await getLocationOfBlockConnection(
-    browser,
-    targetBlock.id,
-    targetConnection,
-  );
+  let draggedLocation;
+  let targetLocation;
+
+  if (mutatorBlockId) {
+    draggedLocation = await getLocationOfBlockConnection(
+      browser,
+      draggedBlock,
+      draggedConnection,
+      mutatorBlockId,
+    );
+    targetLocation = await getLocationOfBlockConnection(
+      browser,
+      targetBlock,
+      targetConnection,
+      mutatorBlockId,
+    );
+  } else {
+    draggedLocation = await getLocationOfBlockConnection(
+      browser,
+      draggedBlock.id,
+      draggedConnection,
+    );
+    targetLocation = await getLocationOfBlockConnection(
+      browser,
+      targetBlock.id,
+      targetConnection,
+    );
+  }
 
   const delta = {
     x: targetLocation.x - draggedLocation.x,
     y: targetLocation.y - draggedLocation.y,
   };
-  await draggedBlock.dragAndDrop(delta);
-  await browser.pause(200);
+  if (mutatorBlockId) {
+    await dragBlockSelector.dragAndDrop(delta);
+  } else {
+    await draggedBlock.dragAndDrop(delta);
+  }
 }
 
 /**