Frankenstein was revised several times in the early years of its rise to fame–by Percy Shelley, by William Godwin, and, in 1831, by Mary herself.
A collation of the 1818 and 1831 editions of Frankenstein from the University of Pennsylvania: http://knarf.english.upenn.edu/Colv1/ftitle.html
The manuscript of Frankenstein at the Shelley-Godwin Archive: http://shelleygodwinarchive.org/contents/frankenstein/
Anne K. Mellor, “Revising Frankenstein”: http://knarf.english.upenn.edu/Articles/mellor9.html
E.B. Murray, “Changes to the 1823 edition of Frankenstein“: http://knarf.english.upenn.edu/Articles/murray.html
E.B. Murray, “Shelley’s contributions to Frankenstein“: http://knarf.english.upenn.edu/Articles/murray2.html
Blog post on Theodore von Holst’s illustration of Frankenstein: https://romanticillustrationnetwork.com/2016/11/26/image-of-the-month-theodore-von-holst-frankenstein-1831/
“Dreaming in 432Hz” by Unicorn Heads
“Cold Funk” by Kevin MacLeod
“Mesmerize” by Kevin MacLeod
“The Theatrical Poster for Poltergeist III” by Chris Zabriskie
This episode features the voices of Curtis Matzke, Steven Nelson, and Mary Shelly.