It might also be said that White was an admirer of Thurber; the two were friends from the 1920's, when both were members of the staff of the New Yorker.I think it may be going too far to say that Thurber invented these words. The OED cites a letter of E. B. White as its first quotation. Interestingly, this letter was from the same year as The Thirteen Clocks, and Thurber was an admirer of White; so who knows?
"Guzzle" might be obvious, but the word that is usually paired with "zatch" is guggle, not guzzle.Guzzle seems too obvious for anyone to claim as an invention, not to mention the fact that it had been used to mean throat in the 17th c.