Spectral Bears — ruling 1

The checks for black cards is made both at the time you declare attackers and as the ability resolves. If there are any at the time attackers are declared, it won’t trigger at all. If there are any at the time it resolves, the ability will do nothing.

Spectral Bears : règles, fonctionnement et interactions (MTG)

Spectral Bears 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 this creature attacks, if defending player controls no black nontoken permanents, it doesn't untap during your next untap step.

How it works : Spectral Bears

Original English text — Wizards of the Coast / Scryfall

#1August 1, 2008· Wizards of the Coast
The checks for black cards is made both at the time you declare attackers and as the ability resolves. If there are any at the time attackers are declared, it won’t trigger at all. If there are any at the time it resolves, the ability will do nothing.
No other card is named in this ruling.