Stifle + Hidden Gibbon

[Gbj]

What happens if i stifle a not activated Hidden Gibbon enchantment ?
Nothing happens, because the enchantment remains in play, or Hidden Gibbon goes on grave because is not an enchantment and because is not a creature ?
I think the first answer, thanx for advice.

[Jebus]

Ok, lets say you play an instant, and the Gibbons trigger.

You play Stifle, to counter the trigger.

Since you played another Instant, the Gibbons triggers again.

The second trigger resolves before the first, making the Gibbons a creature.  Then Stifle resolves, countering the first trigger.

Of course, this assumes that your opponent controls the Gibbons.

If you controlled it and for some reason wanted to Stifle your own gibbons, the ability is countered and does nothing.  The Gibbons remains in play as an Enchantment.

[DEA]

this works in much the same way as standstill, btw