Persistent Constrictor

• WOTC Official Reminder Textofficial rules
  Persist — When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.

• WWizards of the Coast2024-09-20
  Official Ruling
  If the target creature is an illegal target as Persistent Constrictor's first ability tries to resolve, it won't resolve and none of its effects will happen. No player will lose life.
• WWizards of the Coast2024-09-20
  Official Ruling
  If a creature has +1/+1 counters and -1/-1 counters on it, state-based actions remove the same number of each so that it has only one kind of those counters on it. A creature's persist ability can bring it back again if its -1/-1 counters are removed this way.
• WWizards of the Coast2024-09-20
  Official Ruling
  If a creature with persist that has +1/+1 counters on it receives enough -1/-1 counters to cause it to be destroyed by lethal damage or put into its owner's graveyard for having 0 or less toughness, persist won't trigger and the card won't return to the battlefield. That's because persist checks the creature as it last existed on the battlefield, and it still had -1/-1 counters on it at that point.
• WWizards of the Coast2024-09-20
  Official Ruling
  If a card with persist is removed from the graveyard after it dies but before the ability trigger resolves, it won't be returned to the battlefield.
• WWizards of the Coast2024-09-20
  Official Ruling
  Once persist returns the creature, it's considered a new object with no relation to the object that it was. Auras that were attached to it won't return to the battlefield. Equipment that was attached to it will remain unattached. Any counters that were on it won't be put on the new creature.

Rulings via Scryfall