Mummy

The mummy is a new Life State introduced in The Sims 3 World Adventures. Normally, mummies are NPCs but by sleeping in a cursed sarcophagus can turn a Sim into one.

Biology
Mummies are covered in old, flammable rags. Thus if they catch fire, instead of the usual hour a Sim has before he turns to ashes, a mummy will die instantly. Also, mummies are very slow, so a Sim can outrun a mummy if he can flee the ruin he is in. However, being a mummy has it's perks as they are very strong in comparison to normal Sims, so Sims are normally outmatched by mummies unless they have a high Martial Arts skill level. Also, a mummy can outlive a normal Sim by quite a few days.

Also Mummies energy and bladder needs never decay.

Al Simhara
In Al Simhara, their home nation, NPC mummy will normally be inside their sarcophagus resting. However, upon detecting a Sim disturbing their eternal sleep, they will rise from their sarcophagus (where you can pass the night to become one of the mummies) and pick a fight with the Sim that is treasure hunting. If the Sim loses the match, he becomes cursed and if he doesn't plead with the sphinx and acquire a special statue, the Sim will pass away within 2 weeks.