No the Komodo dragon does not and is not able to breathe fire.
It would be cool if they could though but they are not able to breathe fire and that is just a myth.
However the Komodo Dragon is one of the world's biggest dragons and can kill pigs, deer and water buffalo with their mouths.
Because of the ability to injure or kill someone or something with their mouths very easily the Komodo Dragon does not make a good pet.
I would not recommend having a Komodo Dragon as a pet because they can be deadly.