Nightmare Shepherd

2020-01-24 Any enters-the-battlefield abilities of the copied creature will trigger when the token enters the battlefield. Any "as [this creature] enters the battlefield" or "[this creature] enters the battlefield with" abilities of the creature will also work.

2020-01-24 If something becomes a copy of the token, the copy is also a 1/1 and a Nightmare.

2020-01-24 If the copied creature had {X} in its mana cost, X is considered to be 0.

2020-01-24 If the copied creature was copying something else, then the token enters the battlefield as whatever that creature copied.

2020-01-24 If the token is a copy of a creature whose power and toughness are defined by an ability (usually printed as */* or similar), the token doesn't copy the ability that defines its power and toughness. It remains a 1/1 creature.

2020-01-24 The token copies exactly what was printed on the original creature and nothing else (unless that creature is copying something else; see below). It doesn't copy whether that creature was tapped or untapped, whether it had any counters on it or Auras or Equipment attached to it, or any non-copy effects that had changed its power, toughness, types, color, or so on.

2020-01-24 The token copies the creature as it last existed on the battlefield before it died, not as it existed in the graveyard before it was exiled.