Bag Swinging Elf

When Bag Swinging Elf enters the battlefield, create four 0/1 colorless Gift artifact creature tokens.
Whenever Bag Swinging Elf attacks, you may tap X untapped Gift artifacts you control. If
you do, Bag Swinging Elf gets +X/+0 until
end of turn and deals X damage to the player
or planeswalker it's attacking.