Aldrich Killian (Iron Man 3) breathing fire.
Gargos (Killer Instinct 2)
Bowser breathing fire in Super Smash Bros. Brawl
Duncan (Firebreather) being a half human and half Kaiju has the power to breathe fire.
Jafar (Aladdin) breathing fire.
Patrick Donovan once accidentally melted a mirror with his fiery breath.
The Dragon Warlock (Charmed)
Reshiram (Pokemon) using a signature move known as Blue Flare.
Kyoko Kirisaki (Black Cat) using her Heat to produce a fireball.
Largo (One Piece) breathing out a Very Fire Net.
Hyottoko (Rurouni Kenshin) placed a 9 liter oil bag in his gut, and can breath fire with a deep exhale and his flint teeth.
Sasuke Uchiha (Naruto) breathing fire.
Godzilla using his Atomic Flame.
Ninetails (Pokemon) using Flamethrower.
Houndoom (Pokemon) using a toxin-fueled Flamethrower.
Flareon (Pokemon) using Fire Spin.
Mega Charizard X (Pokemon Origins) using Fire Blast.
Red-Eyes Black Dragon (Yu-Gi-Oh!) using Black Fire Bullet.
Fire Salt (Steven Universe) is a Gem dust that, should a human ingest it, causes them to spit fire uncontrollably.
Superspicy Curry (Super Smash Bros. series) is a dish that, should anyone ingest it, causes them to spit fire uncontrollably.