Please help with our class story

Today, during shared writing, we wrote the beginning of an alternative story for the Three Little Pigs. First of all we had to decide which characters to use and we had lots of super ideas such as The three little rabbits and the big bad fox, the three little wolves and the big bad pig and the three little builders and the big bad giant. Eventually we decided on the three little knights and the big bad dragon and here is our shared write so far.

The Three Little Knights and the Big Bad Dragon

Once upon a time there were three little knights who lived in a dark, spooky castle. One starry night they were playing noughts and crosses when suddenly they heard stomping footsteps, rumbling roars and scraping claws. They silently tiptoed to the window and saw a dark red, scaly dragon with spikes sharper than a chainsaw and a slithery spotty tail staring back at them from behind a rambling rose bush.

What happens next? We would love to hear what you think could happen next in our story.
Will the dragon attack the knights?
Will a princess come and save them?
Will the knights come up with a cunning plan?

If you have any thoughts, please add them in the comments box. We eagerly await your ideas!