Komodo dragons breathe fire -- sort of. Their mouths collect copious amounts of thick saliva, and in that saliva, feeding on the leavings of the dragons' meals, are billions of bacteria, deadly to mammals, which immediately, when the dragon bites, swim into the bloodstream of the attacked animal and get to work. In just a few hours, even if it manages to get away from the dragon, the prey will die of septic shock. Then all the dragon has to do is track it down by the scent of its blood and tuck in. But this method usually doesn't get used, because this giant lizard has very powerful jaws, and has only to clamp down on a limb or large muscle mass and give an occasional shake from its powerful neck to lacerate the wound, and the prey will eventually bleed to death. Very effective means of hunting, that.
Speaking of scents, the Komodo dragon has an incredible sense of smell. Locals claim it can smell a carcass over 100 miles away. Whether or not this is true, the dragons do swim from island to island whenever they smell opportunity on the wind. Their long, forked tongues poke out of their mouths at regular intervals, tasting the air and anything else they touch for the scent of food. Which usually means blood. They also have keen eyesight and sensitive hearing, and can run up to 25 miles per hour.
The Komodo dragon is currently on my Conservation Hot List. The Smithsonian Institute administers their own Komodo Dragon Conservation Fund, which provides funding for conservation projects concerning Komodo dragons.