Any enters-the-battlefield abilities of the copied token will trigger when the token enters the battlefield. Any “as [this permanent] enters the battlefield” or “[this permanent] enters the battlefield with” abilities of the copied token will also work.

If the copied token is copying something else, then the new token enters the battlefield as whatever that token copied.

Each of the new tokens copies the original characteristics of the appropriate token as stated by the effect that created that token and nothing else (unless that creature is copying something else; see below). It doesn’t copy whether the opponent’s token is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, and so on.

If the copied token has in its mana cost, X is 0. (Most tokens don’t have a mana cost unless they’re copying something else.)