You are no longer fully human, but have taken on some minor traits associated with felines. Your five senses have expanded several orders of magnitude. You can see clearly in near darkness, easily differentiate scents better than any bloodhound, easily track and triangulate sounds around you, etc.
Your head is adorned with an adorable, and quite functional, pair of cat ears. You have very sharp claws that you can easily retract or call to use at your fingertips. A cat tail completes your set of cat features and greatly improves your balance, easily compensating for complex motions to keep you upright. Your body, in general, feels lighter to you and is much easier to move in, granting you an improved acrobatic skill–enough to easily always land on your feet.
You have a special ability enabling you to seek out and find delightfully warm sunbeams and other locations of supreme comfort. At your leisure, you can emit a soft aura around you that enforces others’ perception of your adorableness and your need to be taken care of and protected. You are free to choose which breed of domestic cat you take after.