Gallows at Willow Hill
Artifact
, 
, Tap three untapped Humans you control: Destroy target creature. Its controller creates a 1/1 white Spirit creature token with flying.
John Avon
Avacyn Restored (AVR)
• #215Rulings
If the targeted creature is an illegal target when the ability tries to resolve, the ability won’t resolve and none of its effects will happen. The creature’s controller won’t put a Spirit token onto the battlefield.
(wotc • 2012-05-01)
You can tap any three untapped Humans you control, including ones you haven’t controlled continuously since the beginning of your most recent turn, to pay the cost of the activated ability.
(wotc • 2012-05-01)
Rulings
If the targeted creature is an illegal target when the ability tries to resolve, the ability won’t resolve and none of its effects will happen. The creature’s controller won’t put a Spirit token onto the battlefield.
(wotc • 2012-05-01)
You can tap any three untapped Humans you control, including ones you haven’t controlled continuously since the beginning of your most recent turn, to pay the cost of the activated ability.
(wotc • 2012-05-01)