Rule 706.8d

When applying a copy effect that doesn't copy a certain characteristic, retains an original value for a certain characteristic, or modifies the final value of a certain characteristic, any characteristic-defining ability (see rule 604.3) of the object being copied that defines that characteristic is not copied. Example: Quicksilver Gargantuan is a creature that reads, "You may have Quicksilver Gargantuan enter the battlefield as a copy of any creature on the battlefield, except it's still 7/7." Quicksilver Gargantuan enters the battlefield as a copy of Tarmogoyf, which has a characteristic-defining ability that defines its power and toughness. Quicksilver Gargantuan does not have that ability. It will be 7/7.

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