Onslaught
Enchantment
Whenever you cast a creature spell, tap target creature.
The last thing to go through the mogg's mind was its teeth.
Paolo Parente
The List (PLST)
• #EXO-92Rulings
A “creature spell” is any spell with the type Creature, even if it has other types such as Artifact or Enchantment. Older cards of type Summon are also Creature spells.
(wotc • 2008-04-01)
The ability is not optional. If you have the only targetable creatures, you have to tap one of your own.
(wotc • 2004-10-04)
Can target an already tapped creature.
(wotc • 2004-10-04)
Rulings
A “creature spell” is any spell with the type Creature, even if it has other types such as Artifact or Enchantment. Older cards of type Summon are also Creature spells.
(wotc • 2008-04-01)
The ability is not optional. If you have the only targetable creatures, you have to tap one of your own.
(wotc • 2004-10-04)
Can target an already tapped creature.
(wotc • 2004-10-04)