Agent O, is an owl that works for the O.W.C.A.; he is brown in color. His first name is unknown, not much is shown of him but he was seen in "Traffic Cam Caper". He was injured, along with Agent D by Dennis the Bunny (a rouge agent) and had his left foot in a cast ("No More Bunny Business"). In "Phineas and Ferb Save Summer", he is instructed to find out "Who's who?"