  Close-in giant planets represent the most significant evidence of planetary
migration. If large exomoons form around migrating giant planets which are more
stable (e.g. those in the Solar System), what happens to these moons after
migration is still under intense research. This paper explores the scenario
where large regular exomoons escape after tidal-interchange of angular momentum
with its parent planet, becoming small planets by themselves. We name this
hypothetical type of object a \textit{ploonet}. By performing semi-analytical
simulations of tidal interactions between a large moon with a close-in giant,
and integrating numerically their orbits for several Myr, we found that in
$\sim$50 per cent of the cases a young ploonet may survive ejection from the
planetary system, or collision with its parent planet and host star, being in
principle detectable. Volatile-rich ploonets are dramatically affected by
stellar radiation during both planetocentric and siderocentric orbital
evolution, and their radius and mass change significantly due to the
sublimation of most of their material during time-scales of hundred of Myr. We
estimate the photometric signatures that ploonets may produce if they transit
the star during the phase of evaporation, and compare them with noisy
lightcurves of known objects ("Kronian" stars and non-periodical dips in dusty
lightcurves). Additionally, the typical transit timing variations (TTV) induced
by the interaction of a ploonet with its planet are computed. We find that
present and future photometric surveys' capabilities can detect these effects
and distinguish them from those produced by other nearby planetary encounters.
