Need to create class which could not been destroyed by GC

Undead_beta

using System;
namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            Undead undead = null;
            try
            {
                undead = new Undead(null);
            }
            catch { }

            for (int i = 0; i < 15; i++)
            {
                Console.Write(new WeakReference(undead).IsAlive ? "Alive " : "Dead ");
                Console.WriteLine(undead == null ? "No link" : "Link exist");

                new HugeObject();
            }

            Console.ReadLine();
        }
    }

    class Undead
    {
        private object o;
        public string str = "Undead dead";

        public Undead(object o)
        {
            this.o = o;
            Console.WriteLine("I will die");
            throw new NotImplementedException();
        }

        ~Undead()
        {
            try
            {
                new Undead(this);
            }
            catch { }
            if (o != null)
            {
                Console.WriteLine(((Undead) o).str);
                str = "Kill me plz";
            }
        }
    }

    class HugeObject
    {
        string o = new string('0', 1024 * 1024 * 8);
    }
}