Well that’s easy-- It’s not like she had the opportunity to get off early.
Was it a Russian sub?
Was too much vodka involved?
reply to Mahaloth:
Was it a gift to them? No
Was it a gift to someone else? (like maybe taking to someone to give it to them) Yes
Were they transporting it? Yes
Was it a practical joke? No
Was it a scientific experiment? No
No to all
Was there something unusual about Polly as opposed to other reindeer?
Was Polly the actual name this particular reindeer was given by the people on the sub or some other people?
If so, is there a reason why Polly got that name, as opposed to some other name? And is it relevant to the puzzle?
reply to Aspidistra:
Was there something unusual about Polly as opposed to other reindeer? No
Was Polly the actual name this particular reindeer was given by the people on the sub or some other people? Not sure. Her actual name was Pollyanna. I am guessing that the folks on the sub named her.
If so, is there a reason why Polly got that name, as opposed to some other name? And is it relevant to the puzzle? **No. The name is not important. And yet maybe it is because those men who lived underwater all that time appear to have grown mighty fond of their passenger. Morale and optimism go together. And even when Polly accidentally ate some navigation charts she was OK by everyone. Supposedly they wanted to keep the reindeer in the torpedo room, but she liked crawling under the captain’s bunk to sleep…and it was allowed!
I guess what I am looking for is why a military submarine would transport a gift reindeer for six weeks. It’s not like* McHale’s Navy* or something. This is a real military with strict rules and doing critical work.**
Was the reindeer…
Intended to restore an endangered population?
Some sort of symbolic good will gesture?
Intended for breeding?
Was Polly equipped with some sort of tracking device?
Was she meant to be a spy?
Was she taken to a zoo?
Was she taken to the North Pole?
Other than reindeer, did this outing have anything to do with Christmas at all?
reply to Go_Arachnid_Laser
Was the reindeer…
Intended to restore an endangered population? No
Some sort of symbolic good will gesture? Yes
Intended for breeding? No
reply to Knowed Out:
Was Polly equipped with some sort of tracking device? No
Was she meant to be a spy? No
Was she taken to a zoo? Yes
Was she taken to the North Pole? No
Other than reindeer, did this outing have anything to do with Christmas at all? No.
Was underwater (submarine) transport required for Pollyanna to get to her final destination?
Was she transported beneath the polar ice cap?
**reply to Cheesesteak/b]:
Was underwater (submarine) transport required for Pollyanna to get to her final destination? Yes.
Was she transported beneath the polar ice cap? I don’t think so, but I am not sure.
Story here or here:
I think this is just about solved. I was hoping someone would mention war or diplomacy, but I will be at work all day and unable to answer questions.
The key is it was during WWII. The Russians and the British were uncomfortable allies. While in contact with the Russians patrolling the North Sea waters, the British sub captain mentioned his wife had trouble moving her baby pram in the snow. The next day the Russians gave the captain a gift for his wife, a live reindeer. Not wanting to appear ungrateful, the captain loaded the reindeer on the sub and for six weeks until returning to England they kept the reindeer on board. Lots of funny stories if you google submarine and reindeer. Polly was famous for a while as the only reindeer to partol underwater during war in a submarine.
I’ll try one. Peter I of Portugal allegedly had his vassals kiss the hand of a corpse. Why?
Was the corpse of someone of political significance?
Was the corpse of someone of religious significance?
Was the corpse of someone of cultural (other than religious) significance?
Was the corpse alleged to be of someone other than who it actually was?
Was the corpse human?
Was the corpse one of Peter’s ancestors?
Was it one of his rivals?
Was it a (non-ancestor) member of his family?
Was it as a man? A woman? A child?
Is the identity of the corpse relevant?
Was it the same corpse every time?
ETA: was it just to get the vassal to do something gross? 
Chronos:
Was the corpse of someone of political significance? Yes
Was the corpse of someone of religious significance? Yes
Was the corpse of someone of cultural (other than religious) significance? Not as significant as the above two
Was the corpse alleged to be of someone other than who it actually was? No
Was the corpse human? Yes
Regallag_The_Axe: Was the corpse one of Peter’s ancestors? No
Was it one of his rivals? No
Was it a (non-ancestor) member of his family? No
Was it as a man? A woman? A child? Woman
Is the identity of the corpse relevant? Yes
Was it the same corpse every time? Yes
ETA: was it just to get the vassal to do something gross? No, it was actually well-intentioned.
Was it a Pope?
No