  Mass loss during the red supergiant (RSG) phase plays a crucial role in the
evolution of an intermediate massive star, however, the underlying mechanism
remains unknown. We aim to increase the sample of well-characterized RSGs at
subsolar metallicity, by deriving the physical properties of 127 RSGs in nine
nearby, southern galaxies presented by Bonanos et al. For each RSG, we provide
spectral types and used \textsc{marcs} atmospheric models to measure stellar
properties from their optical spectra, such as the effective temperature,
extinction, and radial velocity. By fitting the spectral energy distribution,
we obtained the stellar luminosity and radius for 97 RSGs, finding $\sim 50\%$
with log$(L/ \rm L_{\odot}) \geq 5.0$ and 6 RSGs with $R \gtrsim 1400 \,\ \rm
R_{\odot}$. We also find a correlation between the stellar luminosity and
mid-IR excess of 33 dusty, variable sources. Three of these dusty RSGs have
luminosities exceeding the revised Humphreys-Davidson limit. We then derive a
metallicity-dependent $J-K_s$ color versus temperature relation from synthetic
photometry and two new empirical $J-K_s$ color versus temperature relations
calibrated on literature TiO and $J$-band temperatures. To scale our derived,
cool TiO temperatures to values in agreement with the evolutionary tracks, we
derive two linear scaling relations calibrated on $J$-band and $i$-band
temperatures. We find that the TiO temperatures are more discrepant as a
function of the mass-loss rate and discuss future prospects of the TiO bands as
a mass-loss probe. Finally, we speculate that 3 hot, dusty RSGs may have
experienced a recent mass ejection ($12\%$ of the K-type sample) and indicate
them as candidate Levesque-Massey variables.
