[Morthoron]

I had forgotten to look up the mentions of Attercop and the other insults Bilbo throws at the spiders in The Annotated Hobbit, so here goes:

Attercop is from the Middle English atter-cop(pe), itself from Old English at(t)or-coppa, "spider" -- it means, literally, "poison head."

The Oxford English Dictionary defines Tomnoddy as "a foolish or stupid person."

Both Lob and Cob are words for "spider." Lob comes from the Middle-English loppe, lop(p), lob (Old English loppe, lobbe). Cob is rare as a separate word and is probably taken from cobweb (Middle-English coppe-web). In the Princess and the Goblin, however, George MacDonald used cob as a word for goblin.

The Annotated Hobbit is a treasure-trove (literally) of linguistic puns. Here is one regarding the name 'Gollum':

Constance B. Hieatt has noted that "Old Norse gull/goll, of which one inflected form would be gollum, means 'gold, treasure, something precious' and can also mean 'ring,' a point which may have occurred to Tolkien.

and another referring to the "An eye in a blue face" riddle in the 'Riddles in the Dark' chapter:

This riddle cleverly expresses the etymology of the word daisy in riddle form. The flower name comes from the Anglo-Saxon dæges eage ("day's eye"), which alludes to the flower's petals opening in the morning (revealing the yellow center) and closing in the evening. Hence it is the "eye of day" or "day's eye" -- the modern daisy.