Herculean

adjective2

1. •
   Of extraordinary might, power, size, etc.; suggesting Hercules in size or strength.

   • But this is not the best:—look, pr'ythee, Charmian, / How this Herculean Roman does become / The carriage of his chafe. — 1606
2. •
   Requiring a huge amount of work; of extraordinary difficulty.

   • He replied in a dry manner, that I would find it a Herculean task to chastise everybody who should laugh at my expense — 1748