  We present StrayCats: a catalog of NuSTAR stray light observations of X-ray
sources. Stray light observations arise for sources 1--4$^{\circ}$ away from
the telescope pointing direction. At this off-axis angle, X-rays pass through a
gap between optics and aperture stop and so do not interact with the X-ray
optics but, instead, directly illuminate the NuSTAR focal plane. We have
systematically identified and examined over 1400 potential observations
resulting in a catalog of 436 telescope fields and 78 stray light sources that
have been identified. The sources identified include historically known
persistently bright X-ray sources, X-ray binaries in outburst, pulsars, and
Type I X-ray bursters. In this paper we present an overview of the catalog and
how we identified the StrayCats sources and the analysis techniques required to
produce high level science products. Finally, we present a few brief examples
of the science quality of these unique data.
