Get Toothless to slap Jack.
Jack: What?! That's just plain evil.
Merida: Yeah, it is. I like it!
Hiccup: Sigh. Let's just get this over with.
*Toothless slapps Jack with his tail*
Jack: Oww! That hurt!
Merida: Deal with it you oversized snowflake!
Rapunzel: Stop it you two. Come here jack, I'll heal it for you.
