The Book of Unwritten Tales 2

You summon five kobolds; the first two are gotten rid of automatically; you have to take action to get rid of the others.

First - zapped by school visitor (cut scene)
Second - plant will eat one automatically (cut scene)
Third - during conversation with troll, troll kills kobold
Fourth - Manipulating windows causes it to be locked out
Fifth - captured by Wilbur and released on Headmaster Bloch

For the third, if you exhaust all conversations with the troll in talking about the kobolds, you'll trigger him to smash one off the kobold on his shoulder.

For the fourth, you'll find two levers in the hall that open/close windows high up. Pull the right lever down to open the lower window; be patient and you'll see the kobold alight on the upper window. Now pull the left lever down and the upper window will open and drop the kobold out the lower window. Closing them both triggers Wilbur to confirm the kobold is gone.

For the fifth kobold, enter the classroom and see the kobold on the fairy tale book. Take the book and use it on the desk ... it will trigger a trap. After trapping the kobold in the desk, you will open it and the kobold jumps out and bites you ... and you knock it out. You automatically place the kobold in a pencil case and put that in your inventory. Later, you'll release the kobold on the Headmaster to distract him and pinch some fireplace powder.