I once drew a dinosaur at the end of a final I bombed. It didn't elicit any mercy.
We took a bonus test in AP History. I had one question that was too good a joke to pass up (I'd share it, but it's an in-joke to my home town that anyone born in the past 30 years wouldn't get). My teacher nearly fell out of her chair and asked if she could share my answer with the punchline of the joke. I told her she was welcome to if I got the point. I got one point on that test.
Profs in my university are too fair :( They correct everything while hiding the names so sucking up to the teacher does fuck all. It's kinda shitty when you're failing a class and can't talk your way out of it. So yeah, gotta actually study. Stuff's too fair, and that's unfair. (Disclaimer: I don't actually mean most of what I just said)
This is usually what happens in Germany too. Profs really try their hardest to be as fair as possible (in written tests. cleavage makes oral tests unfair). But sometimes, you can actually talk to them. Like the 1st year foreign students who learned german in a year and then jumped straight to academic level...