Personally this one is my favorite it’s graceful elegant and has a deep meaning. A lynx is a solitary wild cat. They hunt alone, using their great sense of hearing and their stealth to move through the forests without being seen by either their prey or those who may be watching. When they do strike, they are fast enough to even catch snowshoe hares. Dementors won’t know what hit them! Kingsley Shacklebolt had a lynx for a a patronus.
Both “shackle” and “bolt” refer to means of imprisonment. Specifically, a shacklebolt is the threaded pin of a shackle allowing the linking of multiple chains and metal cables, which is why his patronus is a lynx (links). His first name, “Kingsley”which suggests royalty, much like a graceful lynx.
Also I was reading more about Patronuses and it turns out a Dolphin is the most common patronus.