This video is from the alien encounter of Dr Reed (Dr Jonathan Reed or John Rutter) which took place in October of 1996. As Rutter (Dr Reed) explained, his alien encounter originated in the Cascade Mountains east of Seattle near Snoqualmie Pass.
While still in the mountains, Rutter came across the creature by accident while he and his dog were hiking in the forest. For unknown reasons his dog apparently attacked the creature. The creature, in reaction to the dog attacking it, began to defend itself. Rutter, seeing his dog was losing the battle with the creature, hit the creature in the head with a large tree branch that he had picked up moments earlier when he first heard his dog growling ferociously at "something".
Thinking he had killed it - he eventually ended up bringing the creature home.
He later conducted and filmed an examination of it in his living room.
This is the full footage of that video.
Some have asked what happened to the creature. Rutter says that he believed it escaped of its own accord. The freezer he had been keeping it in wasn't locked, so it could have easily left any time that it wanted to. So apparently that is what it did.