Hylda of the Icy Crown

Hylda of the Icy Crown's ability will trigger only when an effect instructs you to tap an opponent's creature. It won't trigger if a spell or ability you control instructs an opponent to tap a creature they control. For example, if you control Tangle Wire and an opponent taps an untapped creature they control as part of the resolution of Tangle Wire's triggered ability, Hylda's ability won't trigger.