My thoughts are in blue, words to delete are in red, suggested rephrasing is in orange.

I am contacting you because I am searching for representation for my middle grade novel. I found you through Firstborn by Tor Seidler, a book I read shortly after finishing this one, and after a visit to your website, I thought you’d be a good match. I always tell people not to open with the statement that you are seeking representation... it's kind of obvious. However, the personalization here is nice, so I think it could stay as is and not hurt anything.

Years after a prophecy is first uttered, a wolf pup, Moon, speaks of seeing things in her dreams she’d never encountered in the waking world—a final sign taken by the wolves of Yellowstone to head east, where mountains meet the sea, to escape a certain, or so they think, supervolcanic eruption. Wow, that is a superlong unbroken sentence. Find a way to rephrase this and keep the key components - prophecy, dreams, signs, Yellowstone, escape, volcanic eruption - into two or more concise sentences. Moon befriends Auburn, a runaway house cat, only based on the belief that he is the feline who the prophecy foretells will, albeit vaguely, cast a shadow over the moon and bring peace between the wolves and an enemy they are to meet at their journey’s end. Another really convoluted one here, and I'm confused by the statement at the end - the way it's written it could be interpreted as the peace will be brought both between the wolves themselves, and this unknown enemy, too.

In a time where wild and domestic animals view each other as vermin, the duo’s adversaries are plentiful, from another pack who, fueled by their own prejudice, accuses them both of murder, The murder of who? to the hostile pets at their destination Where are they going? who attack the wolves at any chance they get. Upon a mysterious stranger wolf revealing to Moon the lost ending of the prophecy, which gives the alternate outcome of a war beginning with the quarreling wolves and pets, but spreading so far that it results in the death of half the Earth’s animals, she and Auburn must uncover what exactly he is called to do to prevent this before the deadline it sets. Another really long, really convoluted sentence. You need to take a hard look at every sentence, pull out the relevant elements, and keep the writing more concise.

Like No Place on Earth is a 99,000-word You're already aware that your word count is too high for MG, but the writing in the query itself says a lot about your style. Make sure you're not indulging in convoluted sentences, especially when writing MG. middle grade low fantasy novel that will pique the interest of those who have enjoyed the works of Eliot Schrefer, Katherine Applegate, or Erin Hunter. It blends real-life places with a fantasy world of talking animals whose history and social structures are as complex as ours. It has its low, hopeless points, but not without humor and lightheartedness scattered throughout to balance this. I wouldn't take up all this space explaining that it has humor, and also low points - if the query is doing it's job, you don't have to state these things. Though it is a standalone, it has series potential—I am working on a sequel, following Moon as she goes on another journey, this time across the southwestern United States. I wouldn't bother mentioning a sequel, for various reasons. Say it's a standlone with series potential, and leave it at that.

You need to tell us more about the plot itself. There's a lot of words here, but I don't really know what the problem is -- they are escaping something, there are perils on the way... but what's the goal? What do they want, and what is stopping them from getting it?