[Between Hiccup and Bart's calming rubs and scratches, and Kon's continued inaction, Toothless calms down. He's still shooting Kon wary looks, and will start growling if Kon tries to come nearer to him, but he doesn't look like he's going to pounce at one wrong move.]

Considering it looks like we're going to be stuck together for a while, it'd probably be a good idea to figure out what's causing it, just in case it sets off anything else. Toothless won't attack Kon unless he attacks first, he knows better than that, but I can't say the same for whatever's out there.