Barbo, Enlightened Landwalker

Whenever Barbo enters the battlefield or attacks, search your library for a basic forest and put it onto the battlefield tapped, then shuffle your library.
As long as you control 7 or more basic forests, Barbo becomes a legendary 1/1 red Robin creature token with flying and "Whenever this creature attacks, green creatures you control get +3+3 and gain trample until end of turn."