To play that challenge the quest the following conditions have to be met.
1. Quest is active (when you kill a target creature there is a note there on how many more you still need to kill)
2. Hunt for them in Crows Cemetery (although there is a chance for them to appear using blood pearls, they are more likely to appear on better bait)
3. Defeat the creature three times in combat.
4. Visit the quest giver and turn in the quest.
Once the quest is turned in, you will receive a “ticket”. This is an non-clickable item which puts you in the raffle.
You might want to try the quest again, but the cool down time makes this highly unlikely. Best of luck.