毒息巨龙

Text:

Rulings:

• 11/24/2014 A face-down creature has a converted mana cost of 0. However, its converted mana cost changes when it’s turned face up. Thus, if a creature is turned face up in response to being targeted by Noxious Dragon’s ability, it may become an illegal target.
• 11/10/2020 If a creature on the battlefield has <img src="/Handlers/Image.ashx?size=small&amp;name=X&amp;type=symbol" alt="Variable Colorless" align="absbottom" /> in its mana cost, X is considered to be 0.