Boa Hancock

{2}{w}{w}{t}: Tap target creature. As long as Boa Hancock is tapped target creature doesn't untap on its untap phase. You may skip Boa Hancock's untap phase. If you choose to skip Boa Hancock's untap step you may pay {1}{w}{w} to tap target creature, that creature does not untap on its untap phase as long as Boa Hancock is tapped.