Pushing Up the Daisies means you're dead. You're in the ground under the growing flowers.
Fodder is some bulk material used for fill. Fodder is an archaic term for cattle feed and Cannon Fodder is generally understood to mean expendable army men- just something to blindly shoot at the enemy in large volume. Thus, Coffin Fodder is something used to fill a coffin = your dead body.
Student or Learner