It seems to trick just about everybody's brain on first glance.
A video, which has appeared on Reddit, Twitter, and Instagram, shows an adorable corgi being tossed in the snow.
Social media users were quick to point out that at first glance, it looks like the dog is being tossed out of an airplane, causing a moment of panic.
The shading on the snow and the way the light hits the snow in the background, but not the foreground makes it look like clouds rather than a winter day.
One user even went as far as adding in his own plane to make the illusion appear that much worse.
Another week, another viral optical illusion. Over the last year, they've been a bit of a mixed bag.
In January there was the woman who looked like she had incredibly skinny little cartoon legs, which admittedly was quite good.
Late last year there was one that looked like the hands of God had appeared from nowhere, holding aloft a massive iPhone. Which frankly wasn't quite up to scratch.
This corgi illusion blows both of those out of the sky, having had a lot of people (briefly) believing that the poor dog was about to be thrown out of a plane. Because it does really, really look like that.
The video has gone viral on Reddit, Twitter, and Instagram. It seems to trick just about everybody's brain on first glance. Redditors on the subreddit Confusing Perspective all describe the same experience.
"Omg my stomach dropped when he threw the dog," one wrote. "My heart sank for like a half sec."
"My heart is still racing. I just whispered 'no' under my breath," another wrote, whilst several said they were about to punch their computer in outrage on behalf of the dog.
The dog in question is Karma the corgi, who has his own Instagram of course, so here is the video in its original form. It was posted without any comments about how it is an optical illusion, originally intended as a cute video of a dog enjoying itself.
Let's see how your brain gets on with it.
We're going to assume you were briefly terrified, reached for your phone prepared to dial 911, then flooded by an enormous feeling of relief when you realized this is a snow dog, not a sky dog? Don't worry, you are not alone.
The shading on the snow, and the way the light hits the snow in the background but not the foreground makes the whole scene look like clouds rather than a lovely (and safe) winter day. Just another example of how your brain can easily be tricked without context (such as a handy snowman, or actual sky in the background) or a sense of scale (something, anything, below the "clouds").
FYI the illusion gets even worse when you add a plane.