Tomb Knoll enters the battlefield tapped unless you pay .
: Add or to your mana pool.
Put Tomb Knoll on top of your library: Add to your mana pool.
, , Sacrifice Tomb Knoll: Target player gets a poison counter.
.
: Add 
or to your mana pool.
to your mana pool. , , Sacrifice Tomb Knoll: Target player gets a poison counter.
