Paralyze

Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may pay {4}. If the player does, untap the creature.

30th Anniversary Edition

Vintage Masters

Enchant creature
When Paralyze enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may pay {4}. If he or she does, untap the creature.

Masters Edition

Enchant creature
When Paralyze comes into play, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may pay {4}. If he or she does, untap the creature.

Fifth Edition

When Paralyze comes into play, tap enchanted creature.
Enchanted creature does not untap during its controller's untap phase. That player may pay an additional o4 during his or her upkeep to untap it.

Paralyze can be cast targeting a creature which is already tapped.

The creature can only be untapped using Paralyze once per turn.

Two Paralyzes are not cumulative. Paying either one will untap the creature.

This is a change from the most recent wording. As was the case in the past, Paralyze itself has the last triggered ability, rather than granting that ability to the enchanted creature.