"Our foes are many and mighty, but not as many as the trees or as mighty as the sea."

Waker of the Wilds

{X}{G}{G}: Put X +1/+1 counters on target land you control. That land becomes a 0/0 Elemental creature with haste. It's still a land.

Zendikar Rising Commander

Ixalan Promos

Ixalan

If the ability targets a land that’s already a creature, that land creature’s base power and toughness will become 0/0, overwriting its previous base power and toughness. Other effects that modify its power and/or toughness (including any +1/+1 counters that were on it) will continue to apply.

The land-animation effect lasts indefinitely. It doesn’t wear off during the cleanup step or when you lose control of Waker of the Wilds.