Sorry Duke falls into the most people and most spells require a verbal component.

"Judging by the noise, 'kill it with fire' isn't working on mom there." Duke really shouldn't be as excited about this as the knight sounds, that was one spell use there.

"Either its got a resistance of some sort, or just thick skin. One is worse than the other... Ideas that don't require too many spells or giving only one target to that mouth?" Zuko said it had been feeding on prisoners, that should get across that this thing can eat them, easy. "I've a few other elements of damage-and-hold, which seems like a good starting place."