Nibird, Gifted Burrower

Burrow Gifts: At the beginning of your end step, you may create a Gift Token (a colorless artifact token with "Sacrifice this token: Add one mana of any color.") If you do, target opponent may choose to either draw a card or gain 3 life.
Excavation Dash:
Whenever Nibird attacks, you may pay {1}{g}. If you do, Nibird gains trample until end of turn.