Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.
Whenever a creature enters the battlefield under an opponent's control, you may attach Prison Term to that creature.
Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keywords are activated abilities and will have colons in their reminder text.
The last ability works only if Prison Term is already on the battlefield. You may move it from the creature it’s currently enchanting onto the new creature.