A portable cat carrier has a sliding floor that momentarily and mildly destabilizes a cat's footing to facilitate transferring the cat in and out of the carrier. The floor is the bottom portion of a movable insert that has a receptacle for receiving the cat. The insert has relatively low side panels to provide the cat with a calming, unrestricted side view. After the cat is lowered into the receptacle, the insert is slid horizontally into an outer housing for containing the cat. When the insert is fully inserted within the housing, a front panel of the insert closes the housing's access opening to prevent the cat from escaping. A back panel of the insert has an elevated impassable rear barrier that prevents the cat from jumping into a trapped area between the insert and the outer housing.