  We study Dark Matter production during first order phase transitions from
bubble-plasma collisions. We focus on scenarios where the Dark Matter sector is
secluded and its interaction with the visible sector (including the Standard
Model) originates from dimension-five and dimension-six operators. We find that
such DM is generally heavy and has a large initial velocity, leading to the
possibility of DM being warm today. We differentiate between the cases of
weakly and strongly coupled dark sectors, where, in the latter case, we focus
on glueball DM, which turns out to have very distinct phenomenological
properties. We also systematically compute the Freeze-In production of the dark
sector and compare it with the bubble-plasma DM abundances.
