Morph

Morph is a keyword ability on creatures that allows the player to pay three colorless mana to play the creature face down. The player can then flip that creature face-up by paying a variable Morph cost printed on each card. Many creatures with morph have additional triggered abilities that trigger when they are turned face-up (see Bane of the Living).

All tournament-legal creatures with morph were printed during Onslaught block.

From the Comprehensive Rules:

• 502.26. Morph

• 502.26a Morph is a static ability that functions in any zone from which you could play the card it’s on, and the morph effect works any time the card is face down. “Morph [cost]” means “You may play this card as a 2/2 face-down creature, with no text, no name, no subtypes, no expansion symbol, and a mana cost of {0} by paying {3} rather than its mana cost.” Any time you could play an instant, you may show all players the morph cost for any face-down permanent you control, pay that cost, then turn the permanent face up. This action does not use the stack. (See rule 504, “Face-Down Spells and Permanents.”)

• 502.26b To play a card using its morph ability, turn it face down. It becomes a 2/2 face-down creature card, with no text, no name, no subtypes, no expansion symbol, and a mana cost of {0}. These values are the copiable values of that object’s characteristics. (See rule 418.5, “Interaction of Continuous Effects,” and rule 503, “Copying Objects.”) Put it onto the stack (as a face-down spell with the same characteristics), and pay {3} rather than pay its mana cost. This follows the rules for paying alternative costs. You can use morph to play a card from any zone from which you could normally play it. When the spell resolves, it comes into play with the same characteristics the spell had. The morph effect applies to the face-down object wherever it is, and it ends when the permanent is turned face up.

• 502.26c You can’t play a card face down if it doesn’t have morph.

• 502.26d Any time you could play an instant, you may turn a face-down permanent you control face up. To do this, show all players what the permanent’s morph cost will be when the effect ends, pay that cost, then turn the permanent face up. The morph effect on it ends, and it regains its normal characteristics. Any abilities relating to the permanent coming into play don’t trigger when it’s turned face up and don’t have any effect, because the permanent has already come into play.

• 502.26e If a face-up permanent is turned face down by a spell or ability, it becomes a 2/2 face-down creature, with no text, no name, no subtypes, no expansion symbol, and a mana cost of {0}. These values are the copiable values of that object’s characteristics. (See rule 418.5, “Interaction of Continuous Effects,” and rule 503, “Copying Objects.”) The rules for morph and face-down permanents apply to it normally.

• 502.26f See rule 504, “Face-Down Spells and Permanents,” for more information on how to play cards with morph.