2018-06-08 : 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 copied creature will also work.

2018-06-08 : If the copied creature has {X} in its mana cost, X is 0.

2018-06-08 : If the copied creature is copying something else, the token enters the battlefield as whatever that creature is copying.

2018-06-08 : If the entering creature leaves the battlefield before Bramble Sovereign's ability resolves, use that creature's last known existence on the battlefield to determine the token's characteristics.

2018-06-08 : The token copies exactly what is printed on the creature and nothing else (unless that creature is copying something else; see below). It doesn't copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and/or Equipment attached to it, or any non-copy effects that changed its power, toughness, types, color, and so on.

2018-06-08 : While resolving the triggered ability of Bramble Sovereign, you can't pay {1}{G} multiple times to have a player create more tokens.