Heya, right now, I ask that you have a reference of your character. The novels are pretty recent to Tapas for me and I haven't thought of how we can integrate them into the secret santa. So for now, it's drawing-related only. But whether you do or do not participate, you can fill out the secret santa survey after the event to help with future ideas for the next year.
(The reference doesn't have to be "good," just enough for the person to have an idea of what to draw. But for this year, you'll also have to draw someone else's character.)
The Secret Santa was first meant to be an 'exercise' for artists, giving us a challenge of having to create someone else's OC whilst also having a friendly 'get-together'