diff --git a/03 Animal/csharp/Animal.csproj b/03 Animal/csharp/Animal.csproj
new file mode 100644
index 00000000..20827042
--- /dev/null
+++ b/03 Animal/csharp/Animal.csproj	
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+  </PropertyGroup>
+
+</Project>
diff --git a/03 Animal/csharp/Animal.sln b/03 Animal/csharp/Animal.sln
new file mode 100644
index 00000000..1d81e643
--- /dev/null
+++ b/03 Animal/csharp/Animal.sln	
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.30907.101
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Animal", "Animal.csproj", "{D9A8DAB5-1B29-44A9-B13F-CED17B5A22B9}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{D9A8DAB5-1B29-44A9-B13F-CED17B5A22B9}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D9A8DAB5-1B29-44A9-B13F-CED17B5A22B9}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D9A8DAB5-1B29-44A9-B13F-CED17B5A22B9}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D9A8DAB5-1B29-44A9-B13F-CED17B5A22B9}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {064879D3-A288-4980-8DC4-59653D5EE2DD}
+	EndGlobalSection
+EndGlobal
diff --git a/03 Animal/csharp/Branch.cs b/03 Animal/csharp/Branch.cs
new file mode 100644
index 00000000..52c13037
--- /dev/null
+++ b/03 Animal/csharp/Branch.cs	
@@ -0,0 +1,18 @@
+namespace Animal
+{
+    public class Branch
+    {
+        public string Text { get; set; }
+
+        public bool IsEnd => Yes == null && No == null;
+
+        public Branch Yes { get; set; }
+
+        public Branch No { get; set; }
+
+        public override string ToString()
+        {
+            return $"{Text} : IsEnd {IsEnd}";
+        }
+    }
+}
\ No newline at end of file
diff --git a/03 Animal/csharp/Program.cs b/03 Animal/csharp/Program.cs
new file mode 100644
index 00000000..0d159724
--- /dev/null
+++ b/03 Animal/csharp/Program.cs	
@@ -0,0 +1,152 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+using Animal;
+
+Console.WriteLine(new string(' ', 32) + "ANIMAL");
+Console.WriteLine(new string(' ', 15) + "CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY");
+Console.WriteLine();
+Console.WriteLine();
+Console.WriteLine();
+Console.WriteLine("PLAY 'GUESS THE ANIMAL'");
+Console.WriteLine();
+Console.WriteLine("THINK OF AN ANIMAL AND THE COMPUTER WILL TRY TO GUESS IT.");
+Console.WriteLine();
+
+// Root of the question and answer tree
+Branch rootBranch = new Branch
+{
+    Text = "DOES IT SWIM",
+    Yes = new Branch { Text = "FISH" },
+    No = new Branch { Text = "BIRD" }
+};
+
+string[] TRUE_INPUTS = { "Y", "YES", "T", "TRUE" };
+string[] FALSE_INPUTS = { "N", "NO", "F", "FALSE" };
+
+
+while (true)
+{
+    MainGameLoop();
+}
+
+void MainGameLoop()
+{
+    // Wait fora YES or LIST command
+    string input = null;
+    while (true)
+    {
+        input = GetInput("ARE YOU THINKING OF AN ANIMAL");
+        if (IsInputListCommand(input))
+        {
+            ListKnownAnimals(rootBranch);
+        }
+        else if (IsInputYes(input))
+        {
+            break;
+        }
+    }
+
+    // Walk through the tree following the YES and NO
+    // branches based on user input.
+    Branch currentBranch = rootBranch;
+    while (!currentBranch.IsEnd)
+    {
+        while (true)
+        {
+            input = GetInput(currentBranch.Text);
+            if (IsInputYes(input))
+            {
+                currentBranch = currentBranch.Yes;
+                break;
+            }
+            else if (IsInputNo(input))
+            {
+                currentBranch = currentBranch.No;
+                break;
+            }
+        }
+    }
+
+    // Was the answer correct?
+    input = GetInput($"IS IT A {currentBranch.Text}");
+    if (IsInputYes(input))
+    {
+        Console.WriteLine("WHY NOT TRY ANOTHER ANIMAL?");
+        return;
+    }
+
+    // Interview the user to add a new question and answer
+    // branch to the tree
+    string newAnimal = GetInput("THE ANIMAL YOU WERE THINKING OF WAS A");
+    string newQuestion = GetInput($"PLEASE TYPE IN A QUESTION THAT WOULD DISTINGUISH A {newAnimal} FROM A {currentBranch.Text}");
+    string newAnswer = null;
+    while (true)
+    {
+        newAnswer = GetInput($"FOR A {newAnimal} THE ANSWER WOULD BE");
+        if (IsInputNo(newAnswer))
+        {
+            currentBranch.No = new Branch { Text = newAnimal };
+            currentBranch.Yes = new Branch { Text = currentBranch.Text };
+            currentBranch.Text = newQuestion;
+            break;
+        }
+        else if (IsInputYes(newAnswer))
+        {
+            currentBranch.Yes = new Branch { Text = newAnimal };
+            currentBranch.No = new Branch { Text = currentBranch.Text };
+            currentBranch.Text = newQuestion;
+            break;
+        }
+    }
+}
+
+string GetInput(string prompt)
+{
+    Console.Write($"{prompt}? ");
+    string result = Console.ReadLine();
+    if (string.IsNullOrWhiteSpace(result))
+    {
+        return GetInput(prompt);
+    }
+
+    return result.Trim().ToUpper();
+}
+
+bool IsInputYes(string input) => TRUE_INPUTS.Contains(input.ToUpperInvariant().Trim());
+
+bool IsInputNo(string input) => FALSE_INPUTS.Contains(input.ToUpperInvariant().Trim());
+
+bool IsInputListCommand(string input) => input.ToUpperInvariant().Trim() == "LIST";
+
+string[] GetKnownAnimals(Branch branch)
+{
+    List<string> result = new List<string>();
+    if (branch.IsEnd)
+    {
+        return new[] { branch.Text };
+    }
+    else
+    {
+        result.AddRange(GetKnownAnimals(branch.Yes));
+        result.AddRange(GetKnownAnimals(branch.No));
+        return result.ToArray();
+    }
+}
+
+void ListKnownAnimals(Branch branch)
+{
+    string[] animals = GetKnownAnimals(branch);
+    for (int x = 0; x < animals.Length; x++)
+    {
+        int column = (x % 4);
+        if (column == 0)
+        {
+            Console.WriteLine();
+        }
+
+        Console.Write(new string(' ', column == 0 ? 0 : 15) + animals[x]);
+    }
+    Console.WriteLine();
+}