  Using ASAS-SN data, we find that the bright ($V{\sim}13.5$ mag) variable star
MACHO 80.7443.1718 (ASASSN-V J052624.38-684705.6) is the most extreme heartbeat
star yet discovered. This massive binary, consisting of at least one early
B-type star, has an orbital period of $P_{\rm ASAS-SN}=32.83627\pm0.00846\,{\rm
d},$ and is located towards the LH58 OB complex in the LMC. Both the ASAS-SN
and TESS light curves show extreme brightness variations of ${\sim}40\%$ at
periastron and variations of ${\sim}10\%$ due to tidally excited oscillations
outside periastron. We fit an analytical model of the variability caused by the
tidal distortions at pericenter to find orbital parameters of $\omega=-61.4$
deg, $i=44.8$ deg and $e=0.566$. We also present a frequency analysis to
identify the pulsation frequencies corresponding to the tidally excited
oscillations.
