  We have investigated the light variability in a sample of 22 carbon-rich
post-AGB stars in the Large Magellanic Cloud (LMC) and Small Magellanic Cloud
(SMC), based primarily on photometric data from the OGLE survey. All are found
to vary. Dominant periods are found in eight of them; these periods range from
49 to 157 days, and most of these stars have F spectral types. These eight are
found to be similar to the Milky Way Galaxy (MWG) carbon-rich proto-planetary
nebulae (PPNs) in several ways: (a) they are in the same period range of ~38 to
~160 days, (b) they have similar spectral types, (c) they are (all but one)
redder when fainter, (d) they have multiple periods, closely spaced in time,
with a average ratio of secondary to primary period of ~1.0, and as an
ensemble, (e) they show a trend of decreasing period with increasing
temperature, and (f) they show a trend of decreasing amplitude with decreasing
period. However, they possibly differ in that the decreasing trend of period
with temperature may be slightly offset from that of the MWG. These eight are
classified as PPNs. The other 14 all show evidence of variability on shorter
timescales. They are likely hotter PPNs or young planetary nebulae. However, in
the MWG the numbers of PPNs peak in the F-G spectral types, while it appears
that in the LMC they peak at a hotter B spectral type. One of the periodic ones
shows a small, R Coronae Borealis-type light curve drop.
