When Undercity Eliminator enters, you may sacrifice an artifact or creature. When you do, exile target creature an opponent controls.
With their guild shunned for opening the doors to Phyrexia, some among the Golgari embraced their status as pariahs and took out their bitterness on all who crossed their paths.
You don’t choose a target at the time Undercity Eliminator’s ability triggers. Rather, a second “reflexive” ability triggers when you sacrifice an artifact or creature this way. You choose a target for that ability as it goes on the stack. Each player may respond to this triggered ability as normal.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.