What you need to do?

Much like Chapter 9: Amnesia – The Execution, there are two equally likely routes you could take with this puzzle.
The title is simply: Monster is Slain; which are the monsters the page is talking about do you think?
Storyteller – Monster is Slain Werewolf dies Answer

How to do it
Panel 1

Begin with a Moon scene to have Bernard transform into a Werewolf.
Panel 2

Use a Disguise scene to have the Baron put on his Dragon costume.
Panel 3

Place a Forest scene and have the Werewolf and ‘Dragon’ meet each other. Neither will know what to do!
Panel 4

Use another Disguise scene to have the Baron return his costume.
Panel 5

Use a Professor scene to have the Baron receive a gun from him.
Panel 6

Use a final Forest scene and have the Baron confront the Werewolf Bernard.
Storyteller – Monster is Slain Dragon dies Answer

How to do it
Panel 1

Start with a Disguise scene to have the Baron put on his Dragon costume.
Panel 2

Use a Forest scene to have the ‘Dragon’ scare Bernard.
Panel 3

Use a Professor scene to have Bernard receive a gun.
Panel 4

Use a Forest scene to have Bernard slay the ‘Dragon’.
How did you find this guide? Let me know in the comments.