A viral optical illusion is taking social media by storm, and leaving many people utterly confused.
The mysterious drawing was shared on Twitter with a caption suggesting that what you see reflects which side of your brain is dominant.
"If you're right-brained, you'll see a fish. If you're left-brained, you'll see a mermaid," the post read.
However - much to everyone's confusion - a lot of people reported seeing neither a fish nor a mermaid, but something else completely.
For most users, the sketch looked like one of two things - either a seal, or the head of a donkey.
"It's actually a donkey's disembodied head," one person jokingly tweeted (although, I can see where they're coming from).
Others agreed - but were left questioning whether that left them left-brained or right-brained. "It's a donkey... what kind of brain do I have?" one wrote, while another asked: "I saw a donkey. Am I broken?"
Others were adamant that the drawing showed a cute seal swimming downwards. "It’s a seal," one wrote, while another agreed, writing: "I see the seal. I see neither fish nor mermaid. Although at first, I thought it was a donkey head."
One user was so confident that they were looking at a seal that they created an annotated version of the drawing pointing out the "cute nose going down to mouth," "eyes," and "seal whiskers," adding: "I have conclusively proved this."
Some people were less certain, suggesting that the picture showed both animals depending on which angle you looked at it from. "I see a seal and a horse it just depends which way you hold your phone," they commented.
And while many agreed that it definitely didn't show a fish or a mermaid, one clever person pointed out that it could be a manatee - which wasn't so far from a mermaid.
"Fun fact: sailors would see manatees and believe they were mermaids. I think this sketch could pass as a manatee," they argued.
As for whether you're right or left-brained, there's no way of knowing whether what you see has any real bearing on that. But that isn't stopping people from getting riled up over the tricky optical illusion.
What do you see? Let us know in the comments section.