I've had the Hungry Vampires quest twice in a few turns. The first time, I chose Vampires to appear and was promised a Happiness reward after I defeated them. When I did, I did not get the Happiness reward.
A few turns later, I again got the Hungry Vampires quest. This time, different options were greyed out. The second option, which was greyed out before now gave impossible percentages which totalled more than 100%, 200% in fact. It seemed to be combined with the most recent quest I was just given to open the portal by defeating a troll, which I was working on. I again chose to fight vampires and got messages that vampires/trolls were being spawned. On the map, I only saw the trolls that I was already fighting on the portal but now I had two quests to fight the trolls with two different rewards in my quest queue.

A few turns later, I again got the Hungry Vampires quest. This time, different options were greyed out. The second option, which was greyed out before now gave impossible percentages which totalled more than 100%, 200% in fact. It seemed to be combined with the most recent quest I was just given to open the portal by defeating a troll, which I was working on. I again chose to fight vampires and got messages that vampires/trolls were being spawned. On the map, I only saw the trolls that I was already fighting on the portal but now I had two quests to fight the trolls with two different rewards in my quest queue.

