Gorbag of Minas Morgul

Whenever a Goblin or Orc you control deals combat damage to a player, you may sacrifice it. When you do, choose one —
• Draw a card.
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

The Lord of the Rings: Tales of Middle-earth

You don't choose a mode for Gorbag of Minas Morgul's ability at the time it triggers. Rather, a second "reflexive" ability triggers when you sacrifice a Goblin or Orc this way. You choose a mode for that ability as it goes on the stack. Each player may respond to this triggered ability as normal.