using System;

public class Program

{

    public static void Main()

    {

        string dog = "Dog";

        var dogObj = Activator.CreateInstance(Type.GetType(dog)) as Animal;

        string cat = "Cat";

        var catObj = Activator.CreateInstance(Type.GetType(cat)) as Animal;

        var catSays = new object[]{"meow"};

        var talkingCatObj = Activator.CreateInstance(Type.GetType(cat), catSays);

        Console.WriteLine(dogObj);

        Console.WriteLine(catObj);

        Console.WriteLine(catObj);

    }

}

​

public abstract class Animal

{

    public override string ToString() { return "Type: " + GetType().Name; }

}

​

internal class Cat : Animal

{

    string Say{get; set;}

    public Cat(){

    }

    public Cat(string catSay){

        Say = catSay;

    }

}

​

public class Dog : Animal

{

}