Halbor, Ancient Myr

When Halbor, Ancient Myr enters the battlefield, choose one:
Create {x} 1/1 black myr tokens equal to the
amount of {x} that was payed to cast
Halbor, Ancient Myr.
Create an X/X myr token. where {x} is the
amount of {x} that was payed to cast
Halbor, Ancient Myr.