Predator Ooze — ruling 1

Each time a creature dies, check whether Predator Ooze had dealt any damage to it at any time during that turn. If so, Predator Ooze's ability will trigger. It doesn't matter who controlled the creature or whose graveyard it was put into.

Predator Ooze : règles, fonctionnement et interactions (MTG)

Predator Ooze is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Indestructible (Damage and effects that say "destroy" don't destroy this creature.) Whenever this creature attacks, put a +1/+1 counter on it. Whenever a creature dealt damage by this creature this turn dies, put a +1/+1 counter on this creature.

How it works : Predator Ooze

Original English text — Wizards of the Coast / Scryfall

#1January 22, 2011· Wizards of the Coast
Each time a creature dies, check whether Predator Ooze had dealt any damage to it at any time during that turn. If so, Predator Ooze's ability will trigger. It doesn't matter who controlled the creature or whose graveyard it was put into.
No other card is named in this ruling.