Above these apparent hieroglyphics was a figure of evident pictorial intent, though its impressionistic execution forbade a very clear idea of its nature. It seemed to be a sort of monster, or symbol representing a monster, of a form which only a diseased fancy could conceive. If I say that my somewhat extravagant imagination yielded simultaneous pictures of an octopus, a dragon, and a human caricature, I shall not be unfaithful to the spirit of the thing. A pulpy, tentacled head surmounted a grotesque and scaly body with rudimentary wings; but it was the general outline of the whole which made it most shockingly frightful. Behind the figure was a vague suggestions of a Cyclopean architectural background.
The writing accompanying this oddity was, aside from a stack of press cuttings, in Professor Angell’s most recent hand; and made no pretense to literary style. What seemed to be the main document was headed “CTHULHU CULT” in characters painstakingly printed to avoid the erroneous reading of a word so unheard-of.
H. P. Lovecraft, Collected Stories
What does in his most recent hand mean here?