BLB: Gift Keyword

[Hanmac]

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)

Example:

Parting Gust {W}{W} Instant Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.) Exile target nontoken creature. If the gift wasn’t promised, return that creature to the battlefield under its owner’s control with a +1/+1 counter on it at the beginning of the next end step.

I don't know yet if this should be work like additional cost or as some kind of Replacement Effect

From what I see so far, the 1/1 blue might be hard-coded, while the Fish part might be affected by Card-text-changes.