Vampire

Vampires are tricky because they are a distinct race unto themselves but can also pass along some traits of their race [sunlight sensitivity, needing blood as a food supply, etc] like an infection, but at the same time a vampire parent and a non-vampire parent can create half vampires [called dhampir] that only display some of the traits.

Any other race can become a vampire if 'infected', though those that don't already display traits from being touched by extraplanar entities [tieflings, aasimar, genasi, etc] seem to take to it better.