Painful, but fun!
CONGRATULATIONS!!!!
And yeah, it's true. They don't like fan art, do they?
Nope nope nope.
If you want good grades, just have some sideways fun like sneaking in a dragon or a normal turtle every so often. Or slip in your fan art in with a thumbnail when you have to do "30 thumbnails/concepts". But avoid going directly forward with any licensed, trademarked characters of popular cultural media for your finished pieces. Gets one better grades....it does.
So congrats on cutting loose Klork! You are now Freeee!
Best wishes on a great job.
When's the party?