Phantasmal Image

• WWizards of the Coast2017-03-14
  Official Ruling
  If Phantasmal Image somehow enters the battlefield at the same time as another creature, Phantasmal Image can't become a copy of that creature. You may choose only a creature that's already on the battlefield.
• WWizards of the Coast2017-03-14
  Official Ruling
  If the chosen creature is copying something else (for example, if the chosen creature is another Phantasmal Image), then Phantasmal Image enters the battlefield as whatever the chosen creature copied.
• WWizards of the Coast2017-03-14
  Official Ruling
  Any enters-the-battlefield abilities of the copied creature will trigger when Phantasmal Image enters the battlefield. Any “as [this creature] enters the battlefield” or “[this creature] enters the battlefield with” abilities of the chosen creature will also work.
• WWizards of the Coast2017-03-14
  Official Ruling
  Phantasmal Image copies exactly what was printed on the original creature (unless that creature is copying something else or is a token; see below) and it gains the Illusion creature type and the triggered ability. It doesn't copy whether that creature is tapped or untapped, whether it has any counters on it or Auras attached to it, or any non-copy effects that have changed its power, toughness, types, color, or so on.
• WWizards of the Coast2017-03-14
  Official Ruling
  If the chosen creature is a token, Phantasmal Image copies the original characteristics of that token as stated by the effect that created the token. Phantasmal Image is not a token in this case.
• WWizards of the Coast2017-03-14
  Official Ruling
  The Illusion creature type and the triggered ability that Phantasmal Image gains as part of its copy effect are both copiable values that other effects may copy.
• WWizards of the Coast2017-03-14
  Official Ruling
  If the chosen creature has in its mana cost, X is considered to be 0.

Rulings via Scryfall