Eric Adrian Vaughan or just commonly refers to as Eric Vaughan or Eric, is a male Human in Twokinds. He is a seafaring merchant specialising in Keidran slaves and the owner of the Vaughan Trading Company.

He has a strong relationship with one of his slaves called Kathrin. He saved Kathrin from his Templar brother, Roderick. He views her as a sister, much to her consternation as unbeknownst to him she has a romantic attraction to her owner. Flora also thinks that Eric takes advantage of Kathrin's natural naivety, but Eric revealed he never did so and is teaching her to read human languages.

Eric often depicted as being something of a pervert due to his attraction to Keidran, which is frequently alluded to extend beyond a mere professional interest. His preference for Keidran may possibly because he grew up with Kathrin (who was bred to be sexually appealing to Humans) from the of age of 10. It is hinted he uses his female slaves to satisfy these tastes; mainly posing for nude paintings. His reputation of this is so great that when Mike was under the effects of an illusion and believed he had been transformed into a female, he was sure that if Eric saw him he would make him do the same perverted things. His obsession has led him to become a great fan, and creator of, erotic Keidran artwork. He has recently expanded his portfolio to include Basitins. He may be a pervert, but he is a polite one.