The Descent: Journeys in the Dark (Second Edition) Wiki
Hidden Predator
2 Threat to Purchase
Exhaust this card after setup of an encounter. While this card is exhausted, each monster with the Wilderness monster trait gains:
Ambush: Each time this monster performs an attack that targets a hero that did not have line of sight to this monster at the start of its activation, that attack gains Pierce 2.
This card does not refresh as normal. Refresh this card at the end of each encounter.
Tangled Web 1 Threat

Hidden Predator is a Plot Card that costs 2 Threat Tokens to purchase and 1 Threat Token to exhaust it.