Fireball firing weapon

[llamabeast]

I'm trying to make a weapon that fires a fireball.

I've already concluded that

1) I can't actually make it fire a fireball
2) I just have to make it a projectile weapon and have small area fire as a secondary effect (since #aoe doesn't work)
3) I can't guarantee the weapon will hit, and the small area fire won't get a chance to hurt anyone if the weapon "misses" (I can give it prec 100 to make sure it hits the right square, but it might not hit anyone there).

I can sort of deal with all these things. But I am really finally stuck with the fly sprite. I can't get anything remotely decent, unsurprisingly since they are all little sprites rather than particle effects. So my real question is: how does the fire breath weapon do it? And does anyone have any helpful suggestions?