Enchantment, G (1)
Common
When an opponent casts a creature spell with flying, if Hidden Spider is an enchantment, Hidden Spider becomes a 3/5 Spider creature with reach. (It can block creatures with flying.)
It wants only to dress you in silk.
Illus. Thomas M. Baxa

10/4/2004: When it turns into a creature, it is no longer an enchantment.
4/1/2008: 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.
5/1/2008: 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 the battlefield.
8/1/2008: A noncreature permanent that turns into a creature is subject to the "summoning sickness" rule: It can only attack, and its {T} abilities can only be activated, if its controller has continuously controlled that permanent since the beginning of his or her most recent turn.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander