Herculean bride of The Beast (4)
I believe the answer is:
hebe
'herculean bride' is the definition.
(I've seen this before)
'of the beast' is the wordplay.
'of' says the answer is hidden in the clue.
'HEBE' is hidden in the letters of 'the beast'.
(Other definitions for hebe that I've seen before include "Greek goddess of spring" , "Olympian cupbearer - evergreen garden shrub" , "Goddess of youth and flowering shrub" , "Youth personified" , "Greek goddess of youth, wife of Hercules" .)