Grand Ossuary (Planechase Anthology)

Whenever a creature dies, its controller distributes a number of +1/+1 counters equal to its power among any number of target creatures he or she controls. Whenever you roll chaos, each player exiles all creatures he or she controls and puts X 1/1 green Saproling creature tokens onto the battlefield, where X is the total power of the creatures he or she exiled this way. Then planeswalk.