October seems to be the artists' favorite month, because two of the most important online events for them take place in October. So if you like to draw, be it fanart or original works, this will interest you.
This time I will talk about Inktober. It is an activity that proposes to make an ink drawing every day in October. Thus, if you participate every day, at the end of October you will have 31 ink drawings.
This challenge was devised in 2009 by illustrator Jake Parker (@mrjakeparker) as a way to practice ink drawing to improve his skills and regain the habit of drawing on paper despite the rise of digital media. The original proposal was to draw only in ink, but currently there are no restrictions.
Participating is easy. You must make a drawing on paper every day in October, scan it or take a photo of it and post it on social networks with the hashtags #inktober and #inktober2020 (if you are reading this after 2020, change it to the corresponding year). Most activity is on Twitter, although artists also choose Instagram to participate. That does not mean that you cannot participate on other social networks, or that you just display your drawings on the refrigerator with magnets, as its creator says on the official page.
Starting in 2016, a list of prompts for drawings was added. The official list of prompts for 2020 is this:

The prompts are completely optional, you can draw what you want whenever you want. However, the participants are encouraged to follow the prompts because when you post a drawing on a certain day following the prompt, you will be able to see the drawings other artists made with the same prompt, compare them and see the ideas they had. You will be surprised at the different ideas that come from a single prompt.
Although the challenge was intended to practice ink drawing, there are actually no restrictions. As recommended by its creator, don't feel obligated to use only ink if your workflow is different. So, for example, it is perfectly OK to make a pencil sketch first (something that in fact most artists do), or use colored pencils or other materials, or even drawing and painting digitally on PC.
You will find more information on the official website.
So, if you like to draw and want a challenge tailored for you, then Inktober is for you. If you decide to participate, don't be shy! Share your creations with the world.