Hushwing Gryff — ruling 1

Triggered abilities use the word “when,” “whenever,” or “at.” They’re often written as “[Trigger condition], [effect].”

Hushwing Gryff — ruling 2

Abilities that create replacement effects, such as a permanent entering the battlefield tapped or with counters on it, are unaffected.

Hushwing Gryff — ruling 3

Abilities that apply “as [this creature] enters the battlefield,” such as choosing a creature to copy with Mercurial Pretender, are also unaffected.

Hushwing Gryff — ruling 4

Hushwing Gryff’s ability stops a creature’s own enters-the-battlefield triggered abilities as well as other triggered abilities that would trigger when a creature enters the battlefield.

Hushwing Gryff — ruling 5

The trigger event doesn’t have to specify “creatures” entering the battlefield. For example, Amulet of Vigor says “Whenever a permanent enters the battlefield tapped and under your control, untap it.” If a creature enters the battlefield tapped and under your control, Amulet of Vigor’s ability would not trigger. If a land (that isn’t also a creature) enters the battlefield tapped and under your control, Amulet of Vigor’s ability would trigger.

Hushwing Gryff — ruling 6

Look at the permanent as it exists on the battlefield, taking into account continuous effects, to determine whether any triggered abilities will trigger. For example, if you control March of the Machines, which says, in part, “Each noncreature artifact is an artifact creature,” each artifact will be a creature at the time it enters the battlefield and will not cause triggered abilities to trigger.

Hushwing Gryff — ruling 7

If Hushwing Gryff and another creature enter the battlefield at the same time, neither creature entering the battlefield will cause triggered abilities to trigger.

Hushwing Gryff : règles, fonctionnement et interactions (MTG)

Hushwing Gryff 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

Flash Flying Creatures entering don't cause abilities to trigger.

How it works : Hushwing Gryff

Original English text — Wizards of the Coast / Scryfall

#1July 18, 2014· Wizards of the Coast
Triggered abilities use the word “when,” “whenever,” or “at.” They’re often written as “[Trigger condition], [effect].”
No other card is named in this ruling.
#2July 18, 2014· Wizards of the Coast
Abilities that create replacement effects, such as a permanent entering the battlefield tapped or with counters on it, are unaffected.
No other card is named in this ruling.
#3July 18, 2014· Wizards of the Coast
Abilities that apply “as [this creature] enters the battlefield,” such as choosing a creature to copy with Mercurial Pretender, are also unaffected.
No other card is named in this ruling.
#4July 18, 2014· Wizards of the Coast
Hushwing Gryff’s ability stops a creature’s own enters-the-battlefield triggered abilities as well as other triggered abilities that would trigger when a creature enters the battlefield.
No other card is named in this ruling.
#5July 18, 2014· Wizards of the Coast
The trigger event doesn’t have to specify “creatures” entering the battlefield. For example, Amulet of Vigor says “Whenever a permanent enters the battlefield tapped and under your control, untap it.” If a creature enters the battlefield tapped and under your control, Amulet of Vigor’s ability would not trigger. If a land (that isn’t also a creature) enters the battlefield tapped and under your control, Amulet of Vigor’s ability would trigger.
No other card is named in this ruling.
#6July 18, 2014· Wizards of the Coast
Look at the permanent as it exists on the battlefield, taking into account continuous effects, to determine whether any triggered abilities will trigger. For example, if you control March of the Machines, which says, in part, “Each noncreature artifact is an artifact creature,” each artifact will be a creature at the time it enters the battlefield and will not cause triggered abilities to trigger.
No other card is named in this ruling.
#7July 18, 2014· Wizards of the Coast
If Hushwing Gryff and another creature enter the battlefield at the same time, neither creature entering the battlefield will cause triggered abilities to trigger.
No other card is named in this ruling.