I guess that since the Underworld Series people like the idea of being a hybrid.
Actually, the idea of vampiric werewolves predates Underworld by a good number of centuries. As a matter of fact, according to many real life legends, slain werewolves could become undead (such as return as a vampire in the physical form of a wolf or a hyena for example) unless the body is decapitated or cremated. According to what I've read, in some regions of Europe the terms for "vampire" and "werewolf" are synonyms, at least from a historical standpoint. Don't know if the creators of the Underworld movies were aware of parts of old and somewhat obscure werewolf legends like that or if they just simply "made it up," but those movies did not actually completely originate the idea, despite what haters of Underworld say.
Anyway, back on the subject of the topic, you're technically not supposed to be able to transform into a werewolf using the Ring of Hircine without actually being a werewolf. I've heard of some glitches here and there, but I can't remember exactly what they are, and I don't know if it really applies to Vampire Lords either.
Also, @Laxador, Wesley Snipes, and Shinros: Have a fishy stick! [img]http://images.uesp.net/c/c4/Fishystick.jpg[/img]