Garde d'honneur de Tocatli

Replacement effects, such as a permanent entering the battlefield tapped or with counters on it, are unaffected. Abilities that apply “as [this creature] enters the battlefield” are replacement effects.

Tocatli Honor Guard’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. This includes abilities that would trigger when Tocatli Honor Guard itself enters the battlefield.

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

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

The trigger event doesn’t have to specify “creatures” entering the battlefield. For example, Contraband Kingpin has an ability that says “Whenever an artifact enters the battlefield under your control, scry 1.” If an artifact creature enters the battlefield under your control, that ability won’t trigger. If a noncreature artifact enters the battlefield under your control, the ability will trigger.

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.