Hidden Gibbons

Enchantment

When an opponent casts an instant spell, if Hidden Gibbons is an enchantment, Hidden Gibbons becomes a 4/4 Ape creature.

2004-10-04:
When it turns into a creature, it is no longer an enchantment.
2004-10-04:
It changes into a creature even if the spell is countered.
2008-08-01:
The ability triggers when the spell is cast, so it becomes a creature before the spell resolves.
2008-08-01:
A noncreature permanent that turns into a creature can attack, and its {T} 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.