vicious
[A]порочный; злой; злобный; норовистый; загрязненный; дефектный; ошибочный; неправильный; ужасный

He walked strangely, swaying at the hips, thin and tall, vicious and deadly.
Durance had a vicious tongue and used people cruelly.
A particularly vicious back-cast entangled her cast, high in the branches of a nearby, unclimbable tree.
A nasty piece of work, vicious and venomous as a viper!
She knew she was caught in a vicious trap, sliding down a slippery spiral.