The Clone Wars S04E01: Water War

When the king of Mon Cala is assassinated, talks break down between the Mon Calamari people and the Quarren, co-inhabitants of the aquatic world. To stop a civil war, the Republic sends Padmé Amidala and Anakin Skywalker, but unbeknownst to them, the Quarren are already being backed by the Separatists. Now the Jedi must protect Mon Cala's new leader, the young Prince Lee-Char, from the attack.