Skizzik

Kicker {R} (You may pay an additional {R} as you cast this spell.)
Trample, haste
At the beginning of the end step, if this creature wasn't kicked, sacrifice it.

It skitters across Shiv, each tendril hitting the ground with a sharp snap.

Dominaria

Kicker {R} (You may pay an additional {R} as you cast this spell.)
Trample, haste
At the beginning of the end step, if Skizzik wasn't kicked, sacrifice it.

World Championship Decks 2001

Invasion

Kicker o
R (You may pay an additional o
R as you play this spell.)
Trample; haste (This creature may attack and oc
T the turn it comes under your control.)
At end of turn, sacrifice Skizzik unless the kicker cost was paid.

Skizzik's ability checks at each end step whether it was kicked while it was being cast. You don't have to pay its kicker cost each turn (and can't do so, even if you really want to kick it again).

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.