  We present observational data for a peculiar supernova discovered by the
OGLE-IV survey and followed by the Public ESO Spectroscopic Survey for
Transient Objects. The inferred redshift of $z=0.07$ implies an absolute
magnitude in the rest-frame $I$-band of M$_{I}\sim-17.6$ mag. This places it in
the luminosity range between normal Type Ia SNe and novae. Optical and near
infrared spectroscopy reveal mostly Ti and Ca lines, and an unusually red color
arising from strong depression of flux at rest wavelengths $<5000$ \AA. To
date, this is the only reported SN showing Ti-dominated spectra. The data are
broadly consistent with existing models for the pure detonation of a helium
shell around a low-mass CO white dwarf and "double-detonation" models that
include a secondary detonation of a CO core following a primary detonation in
an overlying helium shell.
