  We explore the possibility that GW190412, a binary black hole merger with a
non-equal-mass ratio and significantly spinning primary, was formed through
repeated black hole mergers in a dense super star cluster. Using a combination
of semi-analytic prescriptions for the remnant spin and recoil kick of black
hole mergers, we show that the mass ratio and spin of GW190412 are consistent
with a binary black hole whose primary component has undergone two successive
mergers from a population of $\sim 10M_{\odot}$ black holes in a
high-metallicity environment. We then explore the production of GW190412-like
analogs in the CMC Cluster Catalog, a grid of 148 $N$-body star cluster models,
as well as a new model, behemoth, with nearly $10^7$ particles and initial
conditions taken from a cosmological MHD simulation of galaxy formation. We
show that the production of binaries with GW190412-like masses and spins is
dominated by massive super star clusters with high metallicities and large
central escape speeds. While many are observed in the local universe, our
results suggest that a careful treatment of these massive clusters, many of
which may have been disrupted before the present day, is necessary to
characterize the production of unique gravitational-wave events produced
through dynamics.
