  We present Breakthrough Listen's "Exotica" Catalog as the centerpiece of our
efforts to expand the diversity of targets surveyed in the Search for
Extraterrestrial Intelligence (SETI). As motivation, we introduce the concept
of survey breadth, the diversity of objects observed during a program. Several
reasons for pursuing a broad program are given, including increasing the chance
of a positive result in SETI, commensal astrophysics, and characterizing
systematics. The Exotica Catalog is a 963 entry collection of 816 distinct
targets intended to include "one of everything" in astronomy. It contains four
samples: the Prototype sample, with an archetype of every known major type of
non-transient celestial object; the Superlative sample of objects with the most
extreme properties; the Anomaly sample of enigmatic targets that are in some
way unexplained; and the Control sample with sources not expected to produce
positive results. As far as we are aware, this is the first object list in
recent times with the purpose of spanning the breadth of astrophysics. We share
it with the community in hopes that it can guide treasury surveys and as a
general reference work. Accompanying the catalog is extensive discussion of
classification of objects and a new classification system for anomalies.
Extensive notes on the objects in the catalog are available online. We discuss
how we intend to proceed with observations in the catalog, contrast it with our
extant Exotica efforts, and suggest similar tactics may be applied to other
programs.
