Riders of Rohan

When Riders of Rohan enters, create two 2/2 red Human Knight creature tokens with trample and haste.
Dash {4}{R}{W} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Tales of Middle-earth Commander

When Riders of Rohan enters the battlefield, create two 2/2 red Human Knight creature tokens with trample and haste.
Dash {4}{R}{W}

When Riders of Rohan enters the battlefield, create two 2/2 red Human Knight creature tokens with trample and haste.
Dash {4}{R}{W} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

If a creature enters the battlefield as a copy of or becomes a copy of a creature whose dash cost was paid, the copy won't have haste and won't be returned to its owner's hand.

If you pay the dash cost to cast a creature spell, that card will be returned to its owner's hand only if it's still on the battlefield when its triggered ability resolves. If it dies or goes to another zone before then, it will stay where it is.

You don't have to attack with the creature with dash unless another ability says you do.