Pine Marten

The pine marten is an animal found in Northern Europe belonging to the mustelid family. It is related to other creatures such as the otter and weasel. It is one of the Patronus forms found on the patronus quiz for Pottermore.

Behind the Scenes
When J.K Rowling took the quiz while it was still working on it, she recieved the pine marten which she was happy about due to her fondness for weaselly creatures. However, she took the quiz when it was completed and recieved the heron.