Dreadhorde Butcher — ruling 1

Dreadhorde Butcher’s last known existence on the battlefield is checked to determine its power as its last ability resolves. If its power was 0 or less, the ability resolves with no effect.

Dreadhorde Butcher : règles, fonctionnement et interactions (MTG)

Dreadhorde Butcher 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

Haste Whenever this creature deals combat damage to a player or planeswalker, put a +1/+1 counter on this creature. When this creature dies, it deals damage equal to its power to any target.

How it works : Dreadhorde Butcher

Original English text — Wizards of the Coast / Scryfall

#1May 3, 2019· Wizards of the Coast
Dreadhorde Butcher’s last known existence on the battlefield is checked to determine its power as its last ability resolves. If its power was 0 or less, the ability resolves with no effect.
No other card is named in this ruling.