  There are only a few ``dark galaxy'' candidates discovered to date in the
local Universe. One of the most prominent of them is the SW component of a
merging system HI 1225+01. On the other hand, the number of known very
metal-poor gas-rich dwarfs similar to IZw18 and SBS 0335-052 E,W has grown
drastically during the last decade, from a dozen and a half to about five
dozen. Many of them are very gas-rich, having from ~90 to 99% of all baryons in
gas. For some of such objects that have the deep photometry data, no evidences
for the light of old stars are found. At least a half of such galaxies with the
prominent starbursts have various evidences of interactions, including advanced
mergers. This suggests that a fraction of this group objects can be a kind of
very stable protogalaxies (or ``dark galaxies''), which have recently
experienced strong disturbances from nearby massive galaxy-size bodies. Such a
collision caused the gas instabilities and its collapse with the subsequent
onset of starburst. We briefly discuss the morphology and gas kinematics for
the subsample of the most metal-poor dwarfs that illustrate this picture. We
discuss also the relation of these rare galaxies to the processes by which
``dark galaxies'' can occasionally transform to optically visible galaxies.
