Water calls to water, and the world is left exhausted and withered in its wake.

Brine Elemental

Morph {5}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, each opponent skips their next untap step.

Time Spiral Remastered

Morph {5}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Brine Elemental is turned face up, each opponent skips their next untap step.

The List

Masters 25

Morph {5}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Brine Elemental is turned face up, each opponent skips his or her next untap step.

Duel Decks Anthology: Jace vs. Chandra

Commander 2014

If an effect says that something doesn't untap during its controller's next untap step, that effect applies to the next untap step that isn't skipped.

Skipping your "next" untap step is cumulative. If a player turns two Brine Elementals face up on the same turn, that player's opponents will each skip their next two untap steps.