"For what are leaves but countless blades
To fight a countless foe on high."
—Elvish hymn

Other Elf creatures get +1/+1 and have forestwalk. (They can't be blocked as long as defending player controls a Forest.)

Elvish Champion

Secret Lair Drop

"For what are leaves but countless blades
To fight a countless foe on high."
—Skyshroud hymn

"We've endured your slights to Gaea with the grace of tolerance. Now behold the grace of our ferocity."