you need uni to do it
make them die of make them into a zombie while creating them
You can turn into a bat only when you are a Vampire.
No, you need the university expansion pack to make zombie Sims.
You can't turn into a mermaid in any of the Sims games.
in sims one you can't even turn into a zombie! let alone get 'unzombied'.
Yes, when you use the aging off cheat the entire family's aging will be turned off.
Unfortunately no, you'll need the sims 2 pets to make your sim turn into a werewolf.
In the Sims 2 Deluxe, you can turn into a vampire! When I want my Sims to turn into vampires, I use a special cheat. You hit Control+Shift+C, and a white box will appear at the top of your screen. You type boolprop testingcheatsenabled true, and then you hold down the Shift button, and click on your Sim. A new menue appears, and then you hit the "More" button. You will find "Make Vampire" as a choice. If you click it, your Sim will turn into a vampire! This is the easiest way to turn your Sim into a vampire. Hope this helps!
Ctrl+Shirt+C. A small white bar should appear on the top of your screen. Type in "aging off". Your Sims will no longer age. When you wish to have them age again, repeat, but type in "aging on".
You have to make the relationship with your "bite victim" high enough to be able to turn them into a creature of the night. The vampire option uses the "nightlife" expansion pack for Sims 2. There are instructions for becoming one at the related link.
you have to have the Pets expansion pack to become a werewolfe. you have to be friends with a wolf (they have yellow glowing eyes) when you are friends with a wolf it will bite you, and then at night you turn into a werewolf
You can turn the green on the skin chooser, and make them really distorted, but at the moment we can't really have zombies, but there are ghosts on the sims 3