I always laugh at this one....
Santa Claus, like all pilots, gets regular visits from the Federal Aviation Administration. The FAA examiner arrived for the pre-Christmas flight check. In preparation, Santa had the elves wash the sled and bathe all the reindeer. Santa got his logbook out and made sure all his paperwork was in order. He knew they would examine all his equipment and put his flying skills to the test.
The examiner walked slowly around the sled. He checked the reindeer harnesses, the landing gear, and Rudolf's nose. He painstakingly reviewed Santa's weight and balance calculations for sled's enormous payload. Finally, they were ready for the checkride. Santa got in and fastened his seatbelt and shoulder harness and checked the compass. Then the examiner hopped in carrying, to Santa's surprise, a shotgun.
“What's that for?” asked Santa incredulously.
The examiner winked and said, “I'm not supposed to tell you this ahead of time,” as he leaned over to whisper in Santa's ear, “but you're gonna lose an engine on takeoff.”