Here's why:
* Predicate: The predicate of a sentence tells us what the subject does or is. It usually includes the verb and any objects or complements that follow it.
* Subject: The subject of the sentence is "The lion."
* Verb: The verb is "came."
* Prepositional Phrase: The phrase "down the mountain" acts as an adverbial phrase, modifying the verb "came".
Therefore, the entire phrase "came down the mountain" acts as the predicate, describing what the lion did.