looks like marble to me. marble which could be used as rorschach test^^
you obviously got the answer you expected/wanted to get (devil) but i could also find 5 million other places which look like it so it is only coincidence whatever some people might try to say with it (yeah i know where you can see that in reality)
btw i see no devil in it even when i try but i can find
a bat (small almost in the middle with eyes, mouth, ears and wings
a huge bug body with small extremeties (the whole darker thing in the middle)
the face of a tortoise (something in the middle)
pelvis with thig bones (the lower part)
some funny animal (could be a monkey) dancing with headphones^^ (from the bottom up to the middle of the whole pciture))
futuristic plane (pretty much in the middle)
an ant from above with antenna
hermit crab from above
the head of an anteater but with a wrong mouth^^
and some other stuff^^
