Hidden Spider

• WWizards of the Coast2004-10-04
  Official Ruling
  When it turns into a creature, it is no longer an enchantment.
• WWizards of the Coast2008-04-01
  Official Ruling
  This card now uses the Reach keyword ability to enable the blocking of flying creatures. This works because a creature with flying can only be blocked by creatures with flying or reach.
• WWizards of the Coast2008-05-01
  Official Ruling
  The ability only triggers if the creature spell has flying, regardless of whether an effect would cause the creature to have flying once it entered.
• WWizards of the Coast2008-08-01
  Official Ruling
  A noncreature permanent that turns into a creature can attack, and its abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn't matter how long the permanent has been a creature.

Rulings via Scryfall