Winding Constrictor

• WWizards of the Coast2017-02-09
  Official Ruling
  If you would get counters of multiple kinds at the same time, Winding Constrictor increases the number of each of those kinds of counters by one. The same is true if counters of multiple kinds would be placed on an artifact or creature you control.
• WWizards of the Coast2017-02-09
  Official Ruling
  If an artifact or creature you control would enter the battlefield with a number of any kind of counters on it, it enters with that many plus one instead.
• WWizards of the Coast2017-02-09
  Official Ruling
  If an effect includes multiple instructions to put one or more counters on an artifact or creature, such as Lifecrafter's Gift does, Winding Constrictor's effect applies to each of those instructions.
• WWizards of the Coast2017-02-09
  Official Ruling
  Winding Constrictor's effect can't apply to itself as it's entering the battlefield or to any other permanent entering the battlefield at the same time as it.
• WWizards of the Coast2017-02-09
  Official Ruling
  If you control two Winding Constrictors, the number of counters placed on the artifact or creature is the original number plus two. Three Winding Constrictors adds three to the original number, and so on.
• WWizards of the Coast2017-09-29
  Official Ruling
  If a nonartifact, noncreature permanent (such as a planeswalker) would enter the battlefield with counters on it and become an artifact or a creature on the battlefield due to another card's effect (such as that of Mycosynth Lattice), Winding Constrictor's effect will give that permanent another of those counters.

Rulings via Scryfall