The Weatherseed Treaty [Dominaria United]

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)

I — Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

II — Create a 1/1 green Saproling creature token.

III — Domain — Target creature you control gets +X/+X and gains trample until end of turn, where X is the number of basic land types among lands you control.