Answer:
Watcher
Explanation:
A person who looks at something is known as a watcher.
I believe "vehement" is the correct answer. It means that it shows strong, powerful, passionate speech and tone.
You didn't italize or mark the phrase, but I see one good candidate:
"The circus animal trainer" is in a way another name given to Mervin, a kind of "renaming" him: this is called an appositive phrase, so if this was the phrase appositive phrase is the answer! (also, I don't see the other phrases here).