you are probably thinking of "Dead like me"
Yes, Ivykit dies as a kit in the Warrior Cats series. She dies from illness in "The Darkest Hour".
No, everyone dies, regardless of race.
Anthony Horowitz's Alex Rider series
Yes, the Grim Reaper always comes when a Sim dies.
Cherrykit becomes Cherryfall and Molekit becomes Molewhisker as they receive their warrior names in the Warriors series by Erin Hunter.
No-one is mentioned by name.
Death/ The Grim Reaper.
as sapwood dies it becomes all mossy and sticky
If he dies in office, then Dick Cheney becomes President.
They lose their spiritual pressure and recarnate as a human with no memories of their past.
The Grimm Reaper is a sign of Death and usually appears in science fiction and horror films before someone dies. The Grimm Reaper is believe to take the souls of people. Many people do not think the Grimm Reaper is nice.
I'm not sure if there is a scientific name for this relationship but I call it the food chain eg. Grass>Zebra>Lion. Then the Lion dies and decomposes and becomes a sort of fertalizer for the grass that the Zebra eats.