I've enjoyed participating in Inktober for the past few years but I find the medium restriction unnecessary and the intensity of rushing through 31 daily prompts to make for clunky work by even seasoned professionals sometimes.
As such let me introduce, Artoberfest!
Same gist. A month long community art challenge. Any medium. 10 pieces to complete. Randomization of themes using two lists of 20, Subjects of mythical creatures and themes of emotional expressions.
Use the hashtag Artoberfest2019 to keep yourself in the loop. feel free to post process stages. 3 days per piece on average should give you some breathing room to focus more on prolific quality than excessive quantity.