Desolation Giant

Kicker {W}{W} (You may pay an additional {W}{W} as you cast this spell.)
When this creature enters, destroy all other creatures you control. If it was kicked, destroy all other creatures instead.

Commander Anthology Volume II

Kicker {W}{W} (You may pay an additional {W}{W} as you cast this spell.)
When Desolation Giant enters the battlefield, destroy all other creatures you control. If it was kicked, destroy all other creatures instead.

Commander 2015

Time Spiral Timeshifted

Kicker {W}{W} (You may pay an additional {W}{W} as you play this spell.)
When Desolation Giant comes into play, destroy all other creatures you control. If the kicker cost was paid, destroy all other creatures instead.

Apocalypse

Kicker o
Wo
W (You may pay an additional o
Wo
W as you play this spell.)
When Desolation Giant comes into play, destroy all other creatures you control. If you paid the kicker cost, destroy all other creatures instead.

If a card or token enters as a copy of a permanent, the new permanent isn't kicked, even if the original was.

If a spell's kicker cost was paid, the spell is "kicked."

If you copy a kicked spell on the stack, the copy is also kicked. If the copied spell is a permanent spell, the token the copy of that spell becomes when it enters is also kicked.

If you put a permanent with a kicker ability onto the battlefield without casting it, you can't kick it.

The kicker ability doesn't let you pay a kicker cost more than once.

To determine a spell's total cost, start with the mana cost (or an alternative cost if another card's effect allows you to pay one instead), add any cost increases (such as kicker), then apply any cost reductions. The spell's mana value remains unchanged, no matter what the total cost to cast it was.