Clever Impersonator

• WWizards of the Coast2014-09-20
  Official Ruling
  If the chosen permanent is a token, Clever Impersonator copies the original characteristics of that token as defined by the effect that put that token onto the battlefield. Clever Impersonator is not a token.
• WWizards of the Coast2014-09-20
  Official Ruling
  You can choose not to copy anything. In that case, Clever Impersonator enters the battlefield as a 0/0 creature, and it's put into the graveyard immediately (unless something is raising its toughness above 0).
• WWizards of the Coast2014-09-20
  Official Ruling
  If Clever Impersonator enters the battlefield at the same time as another permanent, it can't become a copy of that permanent. You may choose only a nonland permanent that's already on the battlefield.
• WWizards of the Coast2014-09-20
  Official Ruling
  Remember that if you control more than one legendary permanent with the same name, you'll choose one to remain on the battlefield and put the rest into their owner's graveyard.
• WWizards of the Coast2014-09-20
  Official Ruling
  If the chosen permanent is a copy of something else (for example, if the chosen permanent is another Clever Impersonator), then your Clever Impersonator enters the battlefield as whatever the chosen permanent copied.
• WWizards of the Coast2014-09-20
  Official Ruling
  Any enters-the-battlefield abilities of the chosen permanent will trigger when Clever Impersonator enters the battlefield. Any "as [this permanent] enters the battlefield" or "[this permanent] enters the battlefield with" abilities of the chosen permanent will also work.
• WWizards of the Coast2014-09-20
  Official Ruling
  You choose which nonland permanent Clever Impersonator will copy, if any, as it enters the battlefield. This doesn't target that nonland permanent.
• WWizards of the Coast2014-09-20
  Official Ruling
  If the chosen permanent has in its mana cost, X is considered to be 0.
• WWizards of the Coast2014-09-20
  Official Ruling
  If Clever Impersonator enters the battlefield as a copy of a planeswalker, it will enter the battlefield with a number of loyalty counters on it equal to the loyalty printed in the lower right corner of the planeswalker card. It won't copy the number of loyalty counters on the original planeswalker.
• WWizards of the Coast2014-09-20
  Official Ruling
  Clever Impersonator copies exactly what is printed on the chosen permanent (unless that permanent is copying something else or is a token; see below). It doesn't copy whether that permanent is tapped or untapped, whether that permanent has any counters on it or any Auras and/or Equipment attached to it, and it doesn't copy any non-copy effects that have changed that permanent's power, toughness, types, color, abilities, or so on.

Rulings via Scryfall