Life state

Each expansion pack for "The Sims 2" released to date has added an alternate state in which Sims can exist. These states are:
Aliens: Released with the base game. If an adult male sim is abducted while stargazing with the expensive telescope, he returns pregnant with an alien baby, Most of the time, this baby is born with green skin and possibly with solid black eyes, and when transitioning to toddler may express facial features not usually found on normal sims. These attributes can then be passed on when the alien child grows up and reproduces.
Zombies: Released with [(University)]. If a Sim bids between $998 and $4127 when using the Ressurect-O-Nomitron, the Sim they are reviving returns as a zombie. He or she returns with a blue-ish skintone, distorted facial features, and a set zombie personality. Zombies cannot walk, skip, or run-they move with a zombie "shamble". Skill points are also lost. Zombies do not age unless a teen zombie chooses to go to college.
Vampires: Released with [(Nightlife)]. If a Sim is bitten by the "Grand Vampire", he or she joins the world of the undead as well. Sims are bitten only if they have a high relationship with the vampire. Once bitten, the newly created vampire can bite other sims. Vampires can transform into bats and fly around, and if out at night their motives don't decay. However, if they are outside in the sun their motives drop very, very quickly, eventually leading to the vampire's demise.
Servos/Robots: Released with [(Open For Buisness)]. Sims can build robots on the robot creation bench which becomes a member of the sims family.