Pyramid Head

Menace
Whenever Pyramid Head attacks,
you may pay X life.
If you do, target creature gets -X/-X until end of turn.
Whenever a creature dies, if its toughness was
reduced to 0 or less this turn, you may pay {2}{b}.
If you do, create a colorless Enchantment Artifact token
named "Great Knife" with "Equipped creature gets +3/+0
and has menace." Attach it to target creature.