First word that comes to your mind...

Dumbledore: "Now, it's great that you've been saving the school and all Harry, but unfortunately your grades have been a tad low, and, well... perhaps Gandalf could explain it better... hit it, Gandalf!

Gandalf: "YOU SHALL NOT PASS!"

Dumbledore: "Now, it's great that you've been saving the school and all Harry, but unfortunately your grades have been a tad low, and, well... perhaps Gandalf could explain it better... hit it, Gandalf!

Gandalf: "YOU SHALL NOT PASS!"

*insert quirky signature here*

Dumbledore: "Now, it's great that you've been saving the school and all Harry, but unfortunately your grades have been a tad low, and, well... perhaps Gandalf could explain it better... hit it, Gandalf!

Gandalf: "YOU SHALL NOT PASS!"

Dumbledore: "Now, it's great that you've been saving the school and all Harry, but unfortunately your grades have been a tad low, and, well... perhaps Gandalf could explain it better... hit it, Gandalf!

Gandalf: "YOU SHALL NOT PASS!"

Dumbledore: "Now, it's great that you've been saving the school and all Harry, but unfortunately your grades have been a tad low, and, well... perhaps Gandalf could explain it better... hit it, Gandalf!

Gandalf: "YOU SHALL NOT PASS!"

*insert quirky signature here*

I only put my signature on big cheques.

Dumbledore: "Now, it's great that you've been saving the school and all Harry, but unfortunately your grades have been a tad low, and, well... perhaps Gandalf could explain it better... hit it, Gandalf!

Gandalf: "YOU SHALL NOT PASS!"