Two daily strips published on the same date in 1939: August 12.
The first one is obviously a Mickey Mouse daily by Floyd Gottfredson and Bill Wright, featuring the Blot.
But the second one is the less familar Inspector Wade. "The Feathered Serpent" looks a lot like the Blot, I'd say...
Now, the Blot first appeared in May 1939. I wonder when the Serpent first showed his black hood? Before or after the Blot first appeared?
My friend Germund von Wowern found this strip and will (hopefully) research further. If he comes up with more info I'll post it on the blog.