1. A literary device used by the author in the first sentence is hyperbole.
Hyperbole refers to the act of writing or something in an exaggerated manner that makes it sound bigger or better. In other words, these are exaggerated claims that are not taken literally.
2. An extended metaphor is a metaphor that sustains the comparison for several lines, or for an entire poem.
An extended metaphor is a comparison between two, unlike objects that can be comprised in more than one sentence or a full paragraph.
Example,
In the excerpt from, As You Like It by William Shakespeare,
<em>“All the world’s a stage, and all the men and women merely players;</em>
<em>They have their exits and their entrances, And one man in his time plays many parts.”</em>
In the above excerpt, Shakespeare has compared life on earth to a stage in the whole sentence.
3. A figure of speech used by the author in the above sentence is a metaphor.
A metaphor is a figure of speech which describes an object or action that isn’t literal in its sense, but it helps in creating a comparison to explain an idea. It states the one thing to be another because they are the same in characteristics.
As in the above passage, William is compared to a clever fox, which doesn't mean he is literally a fox.