Ghost Wolf

[Sirius]

There is only one frame that looks like a wolf and if you watch it a couple of times it's just a smudge the artificing on that whole area is a bit whacked.  Something darts in and hits the tree also at the end with lots of motion blur, the deer doesn't notice it.

Something is moving fast that is either darting back and forth or spinning and the rest is motion blur and artificing.