A word for someone who everyone is scared of?

What would be a word to describe someone that everyone is scared/frightened of?

Example 1:

The employees are scared to ask the boss to extend the deadline because he is ______.

(the blank would be replaced with something like 'scary')

Example 2:

Our dictator is so _____ that nobody dares to oppose him.

Perhaps intimidating will work:

Intimidate

• To make timid or fearful; frighten

• To compel or deter by or as if by threats

The employees are scared to ask the boss to extend the deadline because he is intimidating.

North Korea's dictator is so intimidating that nobody dares to oppose him.

(MWD)

I think that intimidating is the best answer, but just to offer an alternative, consider tyrannical, defined at dictionary.com as:

unjustly cruel, harsh, or severe; arbitrary or oppressive; despotic

It fits nicely in the blanks of both of your examples.