At first, this dog was friendly.
But after fully realizing what was going on, it turned into the ultimate defender of home turf for its owner.
This happened in 2020 and is part of a series where we are looking back at most-watched viral videos.
The video had more than 10 million views at the time this story was published.
A home camera shows that as an intruder enters the home in Oklahoma City, the dog is friendly as the intruder pets it.
But after the homeowner sees the intruder, she screams, sending the dog into an entirely different mood and heroic action.
Watch above to see how the dog scared the intruder away and became legendary on a viral video.