Cat Burglar Nami

Cat Burglar Nami's power is equal to the
number of treasure tokens you control.
When Cat Burglar Nami enters the battlefield,
create a treasure token.
At the beginning of each of your opponent's
upkeep, they may pay {1}. If they don't you
create a treasure token.
If you would create a treasure token, create
two of those tokens instead.
"That will be 300% interest"