Slippery Tusks
J.R.R. Tolkien & the Oxford English Dictionary

An excerpt:

Some words, including walnut, walrus, and wampum, seem to have been assigned to Tolkien because of their particularly difficult etymologies. In the case of walrus, he wrote out many different versions of the etymology - six of which, remarkably, have survived in the archives thanks to Tolkien's habit of recycling discarded slips by turning them over and writing on the other side. In fact walnut, walrus, and wampum were among the few entries singled out by Henry Bradley when the fascicle W to Wash was published in 1921 as containing 'etymological facts or suggestions not given in other dictionaries'. Characteristically, Tolkien continued to puzzle over some of these etymologies long after he had left the OED to take up a post at Leeds University: a notebook survives in the Bodleian Library in Oxford containing many pages of notes on walrus written in the 1920s, and he may have lectured on this topic in Leeds.