Stefan: Hybrid. Turned by Klaus but was not apart of the plan to destroy him thus you not being killed. The only member of Klaus' original hybrids turned still alive other than Tyler Lockwood. Favourite hybrid of Klaus. Broke the sire bond.

Damon: Witch leader of the Gemini coven. You were a twin who was put up for adoption when you were born. You were hidden from the rest of the coven. You and your twin were not affected by the death of Kai Parker having never been officially or knowingly part of the Gemini coven. You knew you were witches and found out to be apart of the Gemini coven from Valerie Tulle and completed the merge ceremony and lived. You possess all the powers listed on the vampire diaries wiki section witch other than transmogrification, projection(unless using a spell), possession and resurrection. 

Tyler: Vampire born in the 1500's who became friends with Stefan and moved along with him since he was turned. 

Jeremy: Evolved werewolf. Part of the Crescent wolf pack. 

Powers include; super strength, super speed, super agility, super durability, healing factor, super senses(as of such another power is lie detection), lycanthrope enhancement, transformation control, werewolf venom, all powers are enhanced during the night of the full moon, immunity to magic bonded silver. 

Weaknesses; blood loss, broken neck, decapitation, fire, heart extraction, link to alphas, magic, mortality, physical trauma, wolfsbane.

Elijah: Supernatural huntress born in the 1300's and was the first supernatural huntress. Possess all of the same abilities and weaknesses as Rayna Cruz, with the difference of having 12 shaman lives instead of eight and not being able to be killed quite as easily as Rayna who was still mortal. You also have complete control of your powers without the hunter's instinct and your blood is poisonous to witches as well as vampires with the cure being your blood mixed with the original hybrid's. If a supernatural being kills you, they will be inflicted with the hunter's curse until you meet them again in a fight.

Klaus: Heretic originally from the Gemini coven in the late 1840's. Turned in 1865 and was the second heretic created. You were a powerful siphoner witch with, after having siphoned a source, almost the same power as Esther Mikaelson. You are now an incredibly powerful witch with the ability to siphon yourself since you are a supernatural being. Part witch part vampire.

For more information on any of these supernatural beings go to this website for more info: http://vampirediaries.wikia.com/wiki/Category:Species 

Leader of the gemini coven would be found under witch.