Eagle-eyed commenter Valet of the Dolls was the first to suggest the uncanny resemblance to legended and unspeakable aquatic hybrids. I think the connection is more sinister still.
It is the Thing on the Doorstep.
There are black zones of shadow close to our daily paths, and now and then some evil soul breaks a passage through. When that happens, the man who knows must strike before reckoning the consequences…The butler, tougher-fibred than I, did not faint at what met him in the hall in the morning. Instead, he telephoned the police. When they came I had been taken upstairs to bed, but the – other mass – lay where it had collapsed in the night. The men put handkerchiefs to their noses.
What they finally found inside Edward’s oddly-assorted clothes was mostly liquescent horror. There were bones, to – and a crushed-in skull.
Well yes, but he paid for that. And the nose is his own; he still has the receipt!