  We present the results of the spectroscopic and photometric monitoring
campaign of ASASSN-15ed. The transient was discovered quite young by the All
Sky Automated Survey for SuperNovae (ASAS-SN). Amateur astronomers allowed us
to sample the photometric SN evolution around maximum light, which we estimate
to have occurred on JD = 2457087.4 +- 0.6 in the r-band. Its apparent r-band
magnitude at maximum was r = 16.91 +- 0.10, providing an absolute magnitude
M(r) ~ -20.04 +- 0.20, which is slightly more luminous than the typical
magnitudes estimated for Type Ibn SNe. The post-peak evolution was well
monitored, and the decline rate (being in most bands around 0.1 mag/d during
the first 25 d after maximum) is marginally slower than the average decline
rates of SNe Ibn during the same time interval. The object was initially
classified as a Type Ibn SN because early-time spectra were characterized by a
blue continuum with superimposed narrow P-Cygni lines of He I, suggesting the
presence of a slowly moving (1200-1500 km/s), He-rich circumstellar medium.
Later on, broad P-Cygni He I lines became prominent. The inferred velocities,
as measured from the minimum of the broad absorption components, were between
6000 and 7000 km/s. As we attribute these broad features to the SN ejecta, this
is the first time we have observed the transition of a Type Ibn SN to a Type Ib
SN.
