Mr. Vratsanos has spun a web of creepiness with his eight LEGged theme. The surfeit of arachnid answers detracted from my enjoyment of the puzzle, especially BITEMARKS. No good, as Huygens might say.
My error occurred where 54A. Antarctic volcano named for a place in the underworld crossed 56D. Hwy. through Minnesota, Wisconsin, and Michigan - another type of hell - kidding! For some reason, I guessed eSTEN, which I was picturing as S10, but US 10 makes a lot more sense. As does EREBUS instead of EREBeS - kidding! :)
I've always thought the word CABOOSE was funny - in a good way. Seeing it in the puzzle today, I wondered where it came from. I looked into it briefly. Its origins are a little murky, but some think it might come from the Dutch word kombuis, meaning galley, because the caboose provided shelter and sometimes cooking facilities for train workers. In other learning opportunities today, I thought I was familiar with the word EPICENE, but it turns out I really had no idea what it meant. Now I do. Thank you NYTX!
Another great entry is ULM. Doesn't that always make you think of Johann Gambolputty de von Ausfern- schplenden- schlitter- crasscrenbon- fried- digger- dingle- dangle- dongle- dungle- burstein- von- knacker- thrasher- apple- banger- horowitz- ticolensic- grander- knotty- spelltinkle- grandlich- grumblemeyer- spelterwasser- kurstlich- himbleeisen- bahnwagen- gutenabend- bitte- ein- nürnburger- bratwustle- gerspurten- mitz- weimache- luber- hundsfut- gumberaber- shönedanker- kalbsfleisch- mittler- aucher von Hautkopft of Ulm? It does me. Every time.
The high incidence of three-letter answers in the grid didn't do it any favors. EDA LeShan was completely unknown to me, but the others, while causing no trouble, also brought no joy.
Horace might be surprised to learn that I figured out 66A. Conductor Georg whose name consists of two musical notes (SOLTI) by running through the solfège song from The Sound of Music. Fa!