Here's my pretty dragon queen Bellus Bestia ready to burn down anything that doesn't agree with her.

Bellus puffs up her neck when she blows fire. On the top of her neck there's a pocket that she fills up with gas and through the 4 holes on her neck she 'inhales' air to mix with the gas making it highly flammable.
So when she wan't to grill someone up she just blows out the gas and lights it with a spark.
This and her huge size doesn't make good with her temper and pride

Character and art by me