If the copied creature is copying something else, then the token enters the battlefield as whatever that creature copied, with the exceptions noted above.

The token copies the creature as it last existed on the battlefield before it died, not as it exists in the graveyard.

If the copied creature is a token, the new token that’s created copies the original characteristics of that token as stated by the effect that created that token, with the exceptions noted above.

Except for power and toughness, the token copies only what was printed on the original creature (unless that creature is copying something else; see below) and adds the color black and the creature type Zombie. 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.

If the copied creature has {X} in its mana cost, X is considered to be 0.

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 chosen creature will also work.