Definition design pattern, is this a thing?

I have created a design showed below. Is this a deign pattern? If so what is its actual name? If it is not a proper design, does there exist a design pattern that does the same but better?

Not tested code

//ExampleFunction
void TestFunction(){
    DefinitionCollection collection = new DefinitionCollection();

    //Creates two enemies with SoldierDefinition (id == 0)
    Enemy enemy1 = new Enemy(collection,0);
    Enemy enemy2 = new Enemy(collection,0);
    //Both enemies got the same reference to MaxHealth and Damage
    //However both enemies got independent currentHealth values

    //enemy2 now looses 20 health, from 70 health to 50 health
    enemy1.Attack(enemy2);

}


//This class are the instances, when a new enemy is made, this is created
public class Enemy {
    //Contains variables that changes per instance
    int currentHealth;
    EnemyDefinition definition;

    public Enemy(DefinitionCollection collection, int definitionID){
        definition = collection.GetDefinition(definitionID);
        currentHealth = definition.MaxHealth;
    }
    public void Attack(Enemy receiver){
        receiver.Damage(definition.Damage);
    }
    public void Damage(int amount){
        currentHealth -= amount;
    }
}

//Keeps track of all the definitions
public class DefinitionCollection{
    private List<EnemyDefinition> Definitions = new List<EnemyDefinition>();
    public DefinitionCollection(){
        Definitions.Add(new SoldierDefinition());
    }

    public EnemyDefinition GetDefinition(int definitionID){
        return Definitions[i];
    }
}

public abstract class EnemyDefinition{
    //Contains constant variables per definition or type
    public int MaxHealth {get; private set;}
    public int Damage {get; private set;}
}

public class SoldierDefinition : EnemyDefinition{
    public SoldierDefinition(){
        MaxHealth = 70;
        Damage = 20;
    }

}