Blind Creeper — ruling 1

This ability triggers off anyone casting a spell, including you, not just Blind Creeper’s controller or an opponent.

Blind Creeper : règles, fonctionnement et interactions (MTG)

Blind Creeper 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

Whenever a player casts a spell, this creature gets -1/-1 until end of turn.

How it works : Blind Creeper

Original English text — Wizards of the Coast / Scryfall

#1December 1, 2004· Wizards of the Coast
This ability triggers off anyone casting a spell, including you, not just Blind Creeper’s controller or an opponent.
No other card is named in this ruling.