The dog, the cat, the donkey, and the rooster sitting in the yard

The phrase "The dog, the cat, the donkey, and the rooster sitting in the yard" is a sentence fragment. It does not form a complete sentence because it lacks a main verb and does not express a complete thought; it's simply a list of subjects with a prepositional phrase. To make it a complete sentence, you could say, "The dog, the cat, the donkey, and the rooster are sitting in the yard."