Many snakes are innocuous.

Solution (By Examveda Team)

Innocuous : not harmful or offensive.
Poisonous : (of a substance or plant) causing or capable of causing death or illness if taken into the body.
Harmful : causing or likely to cause harm.
Deadly : causing or able to cause death.
Ferocious : savagely fierce, cruel, or violent.

Antonym of Innocuous is Harmful