The object will not appear in the hierarchy.

	// Creates 5 planes and hides them from the Hierarchy in the Editor.
	function Start() {
		for(var i : int = 0; i < 5; i++) {
			var createdGO : GameObject = GameObject.CreatePrimitive(PrimitiveType.Plane);
			createdGO.hideFlags = HideFlags.HideInHierarchy;
		}
	}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Start() {
        int i = 0;
        while (i < 5) {
            GameObject createdGO = GameObject.CreatePrimitive(PrimitiveType.Plane);
            createdGO.hideFlags = HideFlags.HideInHierarchy;
            i++;
        }
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Start() as void:
		i as int = 0
		while i < 5:
			createdGO as GameObject = GameObject.CreatePrimitive(PrimitiveType.Plane)
			createdGO.hideFlags = HideFlags.HideInHierarchy
			i++