When Tidebinder Mage enters the battlefield, tap target red or green creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Tidebinder Mage.
The information presented on this site about Magic: The Gathering, both literal and graphical, is copyrighted by Wizards of the Coast.
This website is not produced, endorsed, supported, or affiliated with Wizards of the Coast.