malignant

baleful bitchy dangerous deadliest deadly despiteful evil fatal harmful hostile inhuman inhuman/inhumane jeopardous lethal malevolent malicious malign mephitical mischievous morbid more dangerous more evil more inhuman more inhuman more inhumane more pestilential more poison more poisonous more poisonous mortal most dangerous most evil most inhuman most inhuman most inhumane most pestilential most poison most poisonous most poisonous nasty nocuous opprobrious parlous pernicious pestilential poison/poisonous poisoned poisonous resentful sinister spiteful toxicant unfriendly unkind unwholesome venomous vindictive virulent