2004-12-01 : If the lowest converted mana cost is 3, Culling Scales can destroy itself.

2004-12-01 : If the targeted permanent doesn’t have the lowest converted mana cost when the ability resolves, the ability doesn’t resolve and the permanent isn’t destroyed.

2004-12-01 : Most tokens have a converted mana cost of 0. A token that’s a copy of another permanent or card has a converted mana cost equal to that permanent or card’s converted mana cost.

2004-12-01 : You choose the target. If there’s more than one nonland permanent tied for lowest converted mana cost, you choose which one to target.