Chloe is the name of a robot created by Aloyse von Roddenstein to serve as his assistant. She is programmed to dance.
Upon meeting her for the first time during the block party, Norm falls in love with her. Norm's creator Heinz Doofenshmirtz then convinces Norm to tend to her interests to win her heart, and Norm takes this seriously by challenging Chloe in the dance floor. The plan was a success, and Chloe starts to develop some feelings for him. However, this is shortlived when Rodney arrives to the scene, pulling Chloe away and telling her to stay away from that 'rusted Romeo". Outraged by this turn of events, Doofenshmirtz tells Norm that he doesn't need Chloe (most likely due to his rivalry with Rodney). Despite this, Norm and Chloe opt to maintain their love for each other in spite of their masters' feud. ("Love at First Byte")
It is unknown what happened to Chloe afterwards, even when her master is arrested for his attempt to move the Earth away from the Sun into a new Ice Age. ("Phineas and Ferb Save Summer")