Yoshi is the Grim Reaper

Yoshi is the Grim Reaper is a theory that the Super Mario 64 character Yoshi is the Grim Reaper. The theory comes from another theory that Yoshi is dead in Super Mario 64 DS. One theory that came from it is instead of Yoshi being dead, they stated that Yoshi is death. They stated how Yoshi is different in the two games, which could lead to Yoshi being the Grim Reaper. Other evidence come from the fact that Yoshi doesn't sound like Yoshi. The differences could in fact mean that Yoshi could in fact be the Grim Reaper.

Evidence
Some evidence they are the Grim Reaper is the fact that in the end of Super Mario 64, they give you 99 lives. The fact they give you so much could mean they reaped the previous lives Mario had lost and gave all of them back to Mario.