The motto of November is fishing and good luck. Accordingly, there is Petri Heil card backif you reach at least 20th place in the ranked list in November.
Up to rank 20 you won't lose any stars if you lose, so that should be feasible for anyone interested.
Hearthstone - Better chests for higher ranks
The more ambitious, who play up to the other positions, receive a better reward chest according to their ranks. There is arcane dust and gold cards in there. Especially the milestones at 15/10/5 give significantly better rewards and fewer golden cards.
It doesn't matter if you are Standard format or Wild format plays, the highest rank you have achieved this season counts, regardless of the format.
Another bonus are the stars that you will take with you into the next season. For each rank reached you get a bonus star and you don't have to start from the bottom of the ranking any more.
We don't know whether Nat Pagle will personally present you with the box and the back of the card. The Azeroth fishing grandmaster wishes good luck and success in any case.