Cypher (aka Mr. Reagan) is a member of Morpheus' crew aboard the Nebuchadnezzar in The Matrix. He is portrayed by Joe Pantoliano.
Formerly a bluepill - a human plugged into the Matrix - Cypher one day accepted a red pill from the Resistance and was shown the truth about the world. He served Morpheus aboard the Nebuchadnezzar for years, but eventually became disillusioned with the sorry state of the real world and wished to return to the virtual realm of the Matrix. To this end, he secretly made arrangements with Agent Smith to have him returned to the Machines' power plant and reconnected. In exchange, Cypher was to set a trap that would allow the Agents to capture Morpheus and interrogate him in order to gain access to Zion's mainframe.
When Morpheus took Neo to see the Oracle, Cypher was among the group who jacked in at the Lafayette Hotel, dropping his cellphone into a trash can as a beacon for the Agents. He discretely separated himself from the group when the SWAT team raided the hotel, finding another exit point and jacking out. After awakening on the Neb, Cypher then took a lightning rifle and blasted Tank and Dozer. He then takes the operator's headset and regains contact with the team still jacked in, revealing his plan to them and sadistically killing Apoc and Switch by forcefully unplugging them. He is prepared to do the same to Neo, eager to test the theory that if Neo is indeed the One, then he can't die. Before he can pull Neo's plug, however, Cypher finds that Tank is still alive and now wielding his lightning rifle. Tank fires on Cypher and fries him.