Mid-winter and a troll goes to see an Orc witch-doctor.
"Not feeling well," grumbled the troll, holding his stomach in obvious pain.
"What did you last eat?" enquires the witch-doctor, looking serious.
"Onions," said the troll, looking miserable. He held out one of the offending onions in his hand, which, thoughtfully, he had brought with him.
"That's not an onion. It is a tulip!" announced the Orc, shaking his head. "Never mind. A few weeks in hospital and you'll be out in the spring."