Dragon Slayers are a unique type of people who utilize a form of Lost Magic, Dragon Slayer Magic. Each Dragon Slayer has their own form of Magic, just like each Dragon is a master of their own element. In addition, they also have the ability to consume the element which they wield, just as long as it is not created from their own Magic. Doing so rejuvenates them and enhances their abilities. Dragon Slayers are known to possess keener senses than those of normal humans such as in smell, sight and hearing, as well as distinctive characteristics and features such as slitted pupils and noticeably sharper teeth.
Furthermore, if a Dragon Slayer manages to successfully kill a Dragon, they become stronger after bathing in their blood. However, Dragon Slayers can transform into Dragons themselves through excessive use of their Magic; the most famous example of this is Acnologia, who not only killed nearly every single Dragon in existence, but as a drawback was transformed into a Dragon who was also "not quite a Dragon". The only known way to prevent this "Dragonification", as it were, is for a Dragon to enter the body of a Dragon Slayer via a secret art and sleep there, creating antibodies as they do so. After enough time has passed from the point of their creation, the Dragon Slayer is almost guaranteed to never turn into a Dragon.
Also, when a Dragon Slayer is attracted to someone they love by the opposing gender, both individuals' bodies begin to imprint on the person of their affections.
There are three generations of Dragon Slayers: the First Generation, who learned their Magic from actual Dragons; the Second Generation; who have had Dragon Lacrima implanted into their bodies; and the Third Generation, who are a combination of the previous two generations.
It seems that, for some reason, all Dragon Slayers of an advanced "level" suffer from severe motion sickness. At lower "levels", this isn't much of a problem, as shown with Gajeel prior to the year X791, having rode on both the Super Mage Giant Phantom MK II and the ship to Tenrou Island with ease. However, after three months of intense training, he, too, became vulnerable to motion sickness, having trouble running on a chain of vehicles during the Chariot event. Unless the vehicle is specially designed to accommodate Dragon Slayers, or if they believe the transportation is more of an ally than a vehicle, they will almost definitely experience motion sickness.
This is a list of several known Dragon Slayers: