Your Lizard looks like your Crocodiles distant cousin...
And I like them both, especially your dragon.
You could try making the teeth and spines more 3D though... Nice doodles bro.
aaand, the facepalm's hand can be worked on more; the thumb should be lower than the index finger.
Anyways, keep doodling away! But make sure not to doodle so much during lessons... or you will end up like me, screwing up my tests...