The Mon Calamari Senator is an NPC, an alien Senator from the planet Mon Calamari. A friend of Padme Amidala's, he was presumably no longer with the Senate when it grew corrupt with power, and so wouldn't be onboard the Peace Moon when it blew up, wiping out the entire Galactic Senate.
Revelation of the Sith Edit
Padme and a group of Senators, including Jar Jar Binks, Fang Zar, and the Mon Calamari Senator, confronted Palpatine and Anakin. Padme told Palpatine that she and her fellow Senators were going to overthrow the Senate, much to the other Senators' surprise. The Mon Calamari Senator expressed the shock they were all feeling on hearing this. Palpatine suggested that would be unwise. Senator Jar Jar Binks said he agreed with Palpatine.