可怕的only describe something that is fearsome. For example, 可怕的蛇。 If you want to say "feared" you need to use 害怕 （both adj and verb） For example 我害怕蛇。 （as verb）I am afraid of snakes. 我很害怕。 （as adj）I am terrified.

Eva is right. 可怕 is used for describing the characteristic of somebody or something to indicate its terrible or fearful. It is an adjective. For example，这个人真可怕。/他是一个很可怕的人。（somebody）这部电影真可怕。/这是一部很可怕的电影。（something）. But if you want to express people's own feeling，the word is 害怕. Eva already explained. In a word，fearsome corresponds to two words in Chinese，可怕和害怕，you need choose according to your meaning and context. Because you know，languages is a kind of imbalance.