Wyvern's End

{t}: Add {b} to your mana pool.
Sacrifice a creature: Add {b}{b} to your mana
pool.
When a creature you control dies, put a carcass
counter on wyvern's end.
If there are five carcass counters on wyverns end,
you may sacrifice it to search your deck for a
card named Nakarkos and put it in your hand.