Is there a design pattern for a class using another instance of that same class?

Given the following pseudo code I'm trying to write:

#define ANIMAL_NUMBER 10
#define MALE          1
#define FEMALE        0

class Zoo
{
public:
   Animal* GetAnimal(int id) {return &animal[id];}
private:
   Animal animal[ANIMAL_NUMBER];
};

class Animal
{
public:
  Animal():position_(rand()%2),speed_(rand()%100),life(100){}; //ctor

  void  Kill(Animal* animal)
  { 
    animal->life_ = 0;
  };
  void  KillSlowMaleAnimalsInZoo(void)
  { 
    for(int id=0; id < ANIMAL_NUMBER; id++)
    {
       Animal* animal = Zoo::GetAnimal(id);

       if((animal->life_ > 0) &&
          (animal->sex_ == MALE) &&
          (animal->GetSpeed()<20))
       {
          Kill(animal);
       }
  };
  int   GetSpeed(void)
  { 
    return speed_;
  };
private:
  Sex      sex_;
  int      speed_;
  int      life_;
};

Is there a specific design pattern to answer this particular problem?

What I want is to access another class Animal instance in the Animal class definition itself.