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, which is gross but helpful.

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. The Sim must plead with the sphinx and acquire a special statue or the Sim will pass away within 2 weeks.