Answer:
The full question i believe is "Suddenly, Ollie was a freight train racing into the house". Is the underlined phrase a simile or metaphor"? My answer to this question is Metaphor.
Explanation:
Metaphor is a figurative language in which a thing is regarded as symbolic of something else. In this case 'was a freight train' is symbolic of something else. Metaphor has to do with applying a word or phrase to an object or an action that is not literally applicable.
When a Metaphor is used, the statement does not literally make sense, but then makes sense when the similarities between the two things becomes clear or when the individual understands the connection.