Maiden of the River

Whenever a blue creature enters the battlefield
under your control, create a 1/1 Saproling
creature token.
—
The waves crashed upon the riverbank and she cried
for the ocean again, unable to pass Lord Kenrith's
gates at the mouth of the river. Her tears swept upon
the roots of the forest and stirred the trees with her
magic. Unable to withstand her shrieks and cries,
the now awakened Ents lumbered into Oko's forest.