if y "they" you mean the ancient Egyptians, then they made cat mummies/masks because they believed that cats were the sacred animal of the goddess Bastet or Bast. Bast was often moddled with a woman's body and cat head.
Mummies had mummy masks to show what the person looked like in life.
Mummies that were pharaohs or otherwise royalty were buried with gold masks. Some mummies did not even get a tomb, because they were not wealthy enough to afford them.
GOLD!
Gold
sometimes but not likely
These were placed of the faces of Egyptian mummies, particularly those of pharaohs.
Fed it to the their pets(cats,dogs).
why should we still make mummies today
they thought they were magical
Cats, crocodiles, ibis (a kind of bird), baboons and bulls (or rather, one very special bull known as Apis).
Mummies were usually buried with their prized cats servants and/or their family members and of course their treasure.
in 1300 BC