YES!
draw them in different outfits as long as they're still recognisable.
do joke drawings of them
draw them with other characters
angst
basically somewhat anything as long as it is SFW
NO.
any NSFW/fetish/suggestive artwork whatsoever. i am a minor AND a muslim
Shipping, unless said otherwise.
Gore, unless said otherwise.
Change the race, species or gender of the characters.
Toilet-related stuff [includes piss, scat, f*rting, etc]
Draw underage characters with purposely big breasts or large thighs [not in a digitigrade way]
Anything offensive [eg: bigotry, nazism, zionism, proships, yk the drill] or relating to political slop.