I know cards like Nissa, Worldwaker will get a whole bunch of new lands and make them into Elementals, but are there any way to make all the lands you currently have on the battlefield into Elementals, even for a turn?
If you want your lands to specifically have the "elemental" creature type:
If you don't care what creature type they are, as long as they're creatures:
- Jolrael, Empress of Beasts
- Life
- Living Plane
- Natural Affinity
- Natural Emergence
- Nature's Revolt
- Rude Awakening
If you only need a single type of land to be animated:
- Forests
- Swamps