A pet habitat for cats and the like is provided for secure and stable mounting on or within a window or the like, in a position suspended substantially at an outboard side of the window. The habitat includes an articulated frame carrying a foldable tent-like canopy for facilitated transport and/or storage in a compact collapsed configuration. A spring-loaded clamp bracket enables secure and stable clamp-on frame mounting onto a sill or the like of an open window, whereupon articulated frame components accommodate quick and easy deployment to an erected configuration. When erected, the foldable canopy is stretched over the frame to define a pet enclosure at the outboard side of the window with an access opening for pet ingress/egress from an inboard side of the window. A wall-mounted cat perch and walkway system may be used in combination with the window-mounted pet enclosure.