Nix Card is a supporting antagonist in Star Wars: The Clone Wars. His species is Muun.
He is the Banking Clan represntative in the Republic. Although he claims to be with them he is secretly working with the Separatists along with fellow senators Gume Saam and Lott Dod. In one episode the three wanted to pass a bill that will drain the Republic banks in order to buy more troops to keep the war going. They want this for two reasons:One is because it is part of Count Dooku's master's plan. The other reason is because it would make them rich. However because of the supporters against it he decided to arrange for General Grievous to do an attack in order to scare the senate to pass the bill. They succeed in it at first however in the following episode Senator Amidala convinces people against it.
He later attends a special Zygerrian slave auction.
On Scipio, he arrests Padme Amidala for espionage. He is also in league with Darth Sidious and helped him with his plan to get Rush Clovis into power.
It is unknown what happened to him after the end of the Clone Wars, but it is assumed that he continued working for the Banking Clan.