  We discuss non-standard interpretations of the 750 GeV diphoton excess
recently reported by the ATLAS and CMS Collaborations which do not involve a
new, relatively broad, resonance with a mass near 750 GeV. Instead, we consider
the sequential cascade decay of a much heavier, possibly quite narrow,
resonance into two photons along with one or more invisible particles. The
resulting diphoton invariant mass signal is generically rather broad, as
suggested by the data. We examine three specific event topologies - the antler,
the sandwich, and the 2-step cascade decay, and show that they all can provide
a good fit to the observed published data. In each case, we delineate the
preferred mass parameter space selected by the best fit. In spite of the
presence of invisible particles in the final state, the measured missing
transverse energy is moderate, due to its anti- correlation with the diphoton
invariant mass. We comment on the future prospects of discriminating with
higher statistics between our scenarios, as well as from more conventional
interpretations.
