Here's a collection of links to sites outside of DeviantArt where you can find free plushie patterns. There are well over two hundred choices, so you're sure to find something you like.
However, if you can't find exactly what you're looking for, try adapting one of the patterns. For example, a tiger can easily be turned into a lion, an elephant into a woolly mammoth, an elf into a goblin, or combine the upper half of a mermaid with the lower half of a pony to get a centaur.
Note: some pages may need to be translated or require sign-up to view free patterns.
Check out Pattern-Depot for stuffed toy and costume patterns here on DeviantArt.
I started a new group #Alter-OC-Challenge (https://www.deviantart.com/alter-oc-challenge). This group is to challenge you to play around with your OC as they encounter new an unusual situations. Get those creative juices flowing by participating in one of two weekly challenges (or both, I'm not the boss of you).