The photo has now been shared thousands of times with each new commentator adding their two cents.
Some were certain they could tell a cat from a dog.
Others theorised that science has finally brought together our two favourite domestic animals into one glorious fusion.
And others figured Atchoum must be something else altogether.
Are you ready for the truth?
Atchoum is a cat! The super furry feline shot to fame on Instagram because of his condition - hypertrichosis - which causes extra hair to grow all over.
If you don’t believe us, here’s some video evidence.
If he’s not a cat, then this dog sure has done his homework!