Junk Golem

Reach & Persist (When this dies, if it had no
-1/-1 counters, return it to play under its
owner's control with a -1/-1 counter)
This creature's power & toughness are both equal to the total number of artifacts in all player's graveyards. (Maximum of 10) If you roll a result lower than the above number sacrifice Junk Golem.