You may choose not to untap Old Man of the Sea during your untap step.
: Gain control of target creature with power less than or equal to Old Man of the Sea's power for as long as Old Man of the Sea remains tapped and that creature's power remains less than or equal to Old Man of the Sea's power.
Tap to gain control of a creature with power no greater than Old Man's power. If Old Man becomes untapped, you lose control of this creature; you may choose not to untap Old Man as normal. You also lose control of the creature if Old Man dies or if the creature's power becomes greater than Old Man's.
--This card has no flavor text --