Rebecca
From Halopedia, the Halo wiki
Rebecca is the A.I. of the UNSC Red Horse. Rebecca replaced the former ship's A.I., Chauncey. She is the only known A.I. to have two appearences. Her first appearence is descrbied as "half-Athena, half-Ares" with a feathered Greek headdress and ancient armor. She then later changes her appearence to a flabby, middle-aged Mediterranean woman in a flower dress.