Monstrous
WordNet
adjective
(1) Distorted and unnatural in shape or size; abnormal and hideous
"Tales of grotesque serpents eight fathoms long that churned the seas"
"Twisted into monstrous shapes"
(2) Shockingly brutal or cruel
"Murder is an atrocious crime"
"A grievous offense against morality"
"A grievous crime"
"No excess was too monstrous for them to commit"
(3) Abnormally large